Remove unnecessary calls to self.config()

tests.TestCase:setUp calls self.config(), so there's no need to call
it again.

Change-Id: I02d460d5b0fa7b885f1134198c3215bc69649461

keystone/tests/test_auth_plugin.py

@@ -57,7 +57,6 @@ class NoMethodAuthPlugin(auth.AuthMethodHandler):
 class TestAuthPlugin(tests.TestCase):
     def setUp(self):
         super(TestAuthPlugin, self).setUp()
-        self.config(self.config_files())
         self.load_backends()
 
         # need to register the token provider first because auth controller

keystone/tests/test_v3.py

@@ -91,8 +91,6 @@ class RestfulTestCase(rest.RestfulTestCase):
         self.addCleanup(self.teardown_database)
 
     def load_backends(self):
-        self.config(self.config_files())
-
         self.setup_database()
 
         # ensure the cache region instance is setup