[JBQA-8853] improved test for [EAP6-63][WFLY-424] Domain Controller Discovery Improvements


AS test suite already contains tests of managament operations involving discovery options. This commit just changes behaviour during AS start to ensure that AS start without server and port configured in remote element (WFLY-2918) and with static-discovery option.

https://issues.jboss.org/browse/JBQA-8853