Replace inconsistent skipException messages

Makes skipException message consistent across RBAC base classes.

Change-Id: I32e18111d69e3077749386bd3c81e746bdd43e23
Closes-Bug: #1703402
diff --git a/patrole_tempest_plugin/tests/api/compute/rbac_base.py b/patrole_tempest_plugin/tests/api/compute/rbac_base.py
index 0a3a1f5..4a5dcbf 100644
--- a/patrole_tempest_plugin/tests/api/compute/rbac_base.py
+++ b/patrole_tempest_plugin/tests/api/compute/rbac_base.py
@@ -30,7 +30,7 @@
         super(BaseV2ComputeRbacTest, cls).skip_checks()
         if not CONF.rbac.enable_rbac:
             raise cls.skipException(
-                '%s skipped as RBAC flag not enabled' % cls.__name__)
+                '%s skipped as RBAC testing not enabled' % cls.__name__)
 
     @classmethod
     def setup_clients(cls):