NPE in SSLUtils as not all providers return services

Caused by: java.lang.NullPointerException
	at org.wildfly.security.ssl.SSLUtils.createSslContextFactory(SSLUtils.java:72)
	at org.wildfly.security.ssl.ServerSSLContextBuilder.lambda$build$17(ServerSSLContextBuilder.java:199)
	at org.wildfly.security.OneTimeSecurityFactory.create(OneTimeSecurityFactory.java:45)
	at org.wildfly.extension.elytron.SSLDefinitions$3.lambda$getValueSupplier$65(SSLDefinitions.java:357)
	at org.wildfly.extension.elytron.TrivialService.start(TrivialService.java:53)
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1948)
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1881)
	... 3 more