L2SS-449: Do start the patch

tangostationcontrol/tangostationcontrol/test/clients/test_attr_wrapper.py

@@ -43,6 +43,7 @@ class TestAttributeTypes(base.TestCase):
     def setUp(self):
         # Avoid the device trying to access itself as a client
         self.deviceproxy_patch = mock.patch.object(tangostationcontrol.devices.lofar_device,'DeviceProxy')
+        self.deviceproxy_patch.start()
         self.addCleanup(self.deviceproxy_patch.stop)
 
     class str_scalar_device(lofar_device):