RH-SSO SAML adapter expects a Subject with the NameID field provided

Issue

• SAML adapter throws NPE when receiving the SAML response with no NameID in the Subject.

• The SAML adapter is throwing the following exception:

  ERROR [io.undertow.request] (default task-2) UT005023: Exception handling request to /webapp-template/saml: java.lang.NullPointerException
          at org.keycloak.adapters.saml.profile.AbstractSamlAuthenticationHandler.handleLoginResponse(AbstractSamlAuthenticationHandler.java:410)
          at org.keycloak.adapters.saml.profile.AbstractSamlAuthenticationHandler.handleSamlResponse(AbstractSamlAuthenticationHandler.java:219)
          at org.keycloak.adapters.saml.profile.webbrowsersso.SamlEndpoint.handle(SamlEndpoint.java:44)
          at org.keycloak.adapters.saml.SamlAuthenticator.authenticate(SamlAuthenticator.java:48)
          at org.keycloak.adapters.saml.undertow.AbstractSamlAuthMech.authenticate(AbstractSamlAuthMech.java:115)
          at io.undertow.security.impl.SecurityContextImpl$AuthAttempter.transition(SecurityContextImpl.java:244)
          ...