Fix octavia driver unittests

Commit I566aaa65df4ba7455577a539aa9eebb6cc36a099 removed
_init_rpc_listener from teh driver, and it should be removed from
the tests as well.

Change-Id: I6ba9ac1bd2a97a17f5f407e11ad5397cfc832537

vmware_nsx/tests/unit/services/lbaas/test_octavia_driver.py

@@ -48,7 +48,6 @@ class TestNsxProviderDriver(testtools.TestCase):
             return
         # init the NSX driver without the RPC & certificate
         with mock.patch(DRIVER + '._init_rpc_messaging'), \
-            mock.patch(DRIVER + '._init_rpc_listener'), \
             mock.patch(DRIVER + '._init_cert_manager'):
             self.driver = driver.NSXOctaviaDriver()
             self.driver.client = mock.Mock()