Fixing disable issue

Change-Id: I2ff36d15aaf770528ac3f0c207a3944799355acc
diff --git a/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py b/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py
index 18c8174..d7ba4a2 100644
--- a/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py
+++ b/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py
@@ -194,6 +194,7 @@
         )
 
         with patch.object(self.policy, "get_subscriber") as get_subscriber, \
+            patch.object(self.policy, "update_onu") as update_onu, \
             patch.object(self.policy, "update_subscriber") as update_subscriber:
 
             get_subscriber.return_value = None