Fix or remove MySqlDsDriverInEarReauthTestCase

This test is ignored: https://github.com/jbossas/jboss-eap7/blob/EAP_7.1.0.CR1-dev/testsuite/integration/basic/src/test/java/org/jboss/as/test/integration/jca/reauth/MySqlDsDriverInEarReauthTestCase.java#L52

It depends on the QA instance of MySQL database (via https://github.com/jbossas/jboss-eap7/blob/EAP_7.1.0.CR1-dev/testsuite/integration/basic/src/test/java/org/jboss/as/test/integration/jca/reauth/mysql-ds.xml) which is direly unsuitable for the basic test suite and won't work without access to the VPN.

This testing scenario is covered in the QA tests so I think we can safely get rid of this.