CORD-1677: Update OpenStack synchronizer to match synchronizer core refactoring

Change-Id: I515c8b10f3649507b8b9cf08f3cb166ca12c6240
diff --git a/xos/synchronizer/model_policies/model_policy_ControllerSlice.py b/xos/synchronizer/model_policies/model_policy_ControllerSlice.py
index 125bb7d..4890459 100644
--- a/xos/synchronizer/model_policies/model_policy_ControllerSlice.py
+++ b/xos/synchronizer/model_policies/model_policy_ControllerSlice.py
@@ -24,9 +24,9 @@
         return self.handle_update(controller_slice)
 
     def handle_update(self, controller_slice):
-        my_status_code = int(controller_slice.backend_status[0])
+        my_status_code = int(controller_slice.backend_code)
         try:
-            his_status_code = int(controller_slice.slice.backend_status[0])
+            his_status_code = int(controller_slice.slice.backend_code)
         except:
             his_status_code = 0