Expose underlying cause during InitialContextFactory instantiation

Instantiation an InitialContext might fail with just the follow cause:
javax.naming.NamingException: JBAS011843: Failed instantiate InitialContextFactory com.sun.jndi.ldap.LdapCtxFactory from classloader ModuleClassLoader for Module "deployment.externalContextBindingTest.jar:main" from Service Module Loader

The underlying cause is no longer available.

https://bugzilla.redhat.com/show_bug.cgi?id=1061609