Missing search-base-dn in identity-mapping of Elytron ldap-realm causes NPE

ERROR [io.undertow.request] (default task-1) UT005023: Exception handling request to /print-roles/protected/printRoles: java.lang.RuntimeException: ELY01108: Ldap-backed realm identity search failed
	at org.wildfly.security.auth.realm.ldap.LdapSecurityRealm$LdapRealmIdentity$LdapSearch.search(LdapSecurityRealm.java:976)
	at org.wildfly.security.auth.realm.ldap.LdapSecurityRealm$LdapRealmIdentity.getIdentity(LdapSecurityRealm.java:605)
	at org.wildfly.security.auth.realm.ldap.LdapSecurityRealm$LdapRealmIdentity.exists(LdapSecurityRealm.java:548)
	at org.wildfly.security.auth.realm.ldap.LdapSecurityRealm$LdapRealmIdentity.verifyEvidence(LdapSecurityRealm.java:516)
	at org.wildfly.security.auth.server.ServerAuthenticationContext$NameAssignedState.verifyEvidence(ServerAuthenticationContext.java:1785)
	at org.wildfly.security.auth.server.ServerAuthenticationContext.verifyEvidence(ServerAuthenticationContext.java:656)
	at org.wildfly.security.auth.server.ServerAuthenticationContext$1.handleOne(ServerAuthenticationContext.java:854)
	at org.wildfly.security.auth.server.ServerAuthenticationContext$1.handleOne(ServerAuthenticationContext.java:778)
	at org.wildfly.security.auth.server.ServerAuthenticationContext$1.handleOne(ServerAuthenticationContext.java:895)
	at org.wildfly.security.auth.server.ServerAuthenticationContext$1.handle(ServerAuthenticationContext.java:726)
	at org.wildfly.security.http.util.SecurityIdentityServerMechanismFactory$SecurityIdentityCallbackHandler.handle(SecurityIdentityServerMechanismFactory.java:113)
	at org.wildfly.security.http.impl.UsernamePasswordAuthenticationMechanism.authenticate(UsernamePasswordAuthenticationMechanism.java:69)
	at org.wildfly.security.http.impl.BasicAuthenticationMechanism.evaluateRequest(BasicAuthenticationMechanism.java:151)
	at org.wildfly.security.http.util.SetMechanismInformationMechanismFactory$1.evaluateRequest(SetMechanismInformationMechanismFactory.java:115)
	at org.wildfly.security.http.util.SecurityIdentityServerMechanismFactory$1.evaluateRequest(SecurityIdentityServerMechanismFactory.java:77)
	at org.wildfly.security.http.HttpAuthenticator$AuthenticationExchange.authenticate(HttpAuthenticator.java:106)
	at org.wildfly.security.http.HttpAuthenticator$AuthenticationExchange.access$100(HttpAuthenticator.java:90)
	at org.wildfly.security.http.HttpAuthenticator.authenticate(HttpAuthenticator.java:74)
	at org.wildfly.elytron.web.undertow.server.SecurityContextImpl.authenticate(SecurityContextImpl.java:82)
	at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:55)
	at io.undertow.server.handlers.DisableCacheHandler.handleRequest(DisableCacheHandler.java:33)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.security.handlers.AuthenticationConstraintHandler.handleRequest(AuthenticationConstraintHandler.java:53)
	at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
	at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
	at io.undertow.servlet.handlers.security.ServletSecurityConstraintHandler.handleRequest(ServletSecurityConstraintHandler.java:59)
	at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at org.wildfly.extension.undertow.deployment.GlobalRequestControllerHandler.handleRequest(GlobalRequestControllerHandler.java:46)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:292)
	at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:81)
	at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:138)
	at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:135)
	at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)
	at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)
	at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1680)
	at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1680)
	at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1680)
	at org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1680)
	at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:272)
	at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
	at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:104)
	at io.undertow.server.Connectors.executeRootHandler(Connectors.java:208)
	at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:809)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
	at org.jboss.as.naming.InitialContext.getURLScheme(InitialContext.java:160)
	at org.jboss.as.naming.InitialContext.getURLOrDefaultInitCtx(InitialContext.java:128)
	at javax.naming.directory.InitialDirContext.getURLOrDefaultInitDirCtx(InitialDirContext.java:106)
	at javax.naming.directory.InitialDirContext.search(InitialDirContext.java:286)
	at javax.naming.directory.InitialDirContext.search(InitialDirContext.java:286)
	at org.wildfly.security.auth.realm.ldap.DelegatingLdapContext.search(DelegatingLdapContext.java:319)
	at org.wildfly.security.auth.realm.ldap.LdapSecurityRealm$LdapRealmIdentity$LdapSearch.search(LdapSecurityRealm.java:945)
	... 47 more