[JBPAPP-11080], backport fix of [BZ1064331] NPE in JBWSTokenIssuingLoginModule.

https://issues.jboss.org/browse/JBPAPP-11080
Backport  upstream fix of [BZ1064331] "NPE in JBWSTokenIssuingLoginModule"
https://bugzilla.redhat.com/show_bug.cgi?id=1064331