NamingExceptions not properly handled in InitialContext

The change in https://github.com/jbossas/jboss-eap/commit/db525bf1d90a40eb909c8f915fca787d55f4e7e5#diff-833175ffb151a3398216d6422dadeeeeR112 catches all Exception and rewraps them with NamingException. This behavior is undesirable if the original exception was already a NamingException. Catch and re-throw that exception type as-is before wrapping other exceptions.