fix attribute lookup

Change-Id: Id2ca55bc0da49d8c43a7489e6b3fa7a9ba0fb531
diff --git a/xos/synchronizers/model_policy.py b/xos/synchronizers/model_policy.py
index bf9bba0..0737d63 100644
--- a/xos/synchronizers/model_policy.py
+++ b/xos/synchronizers/model_policy.py
@@ -90,7 +90,7 @@
         walk_inv_deps(delete_if_inactive, instance)
 
     try:
-        policy_handler = getattr(model_policies, policy_name, None)
+        policy_handler = model_policies.get(policy_name, None) # getattr(model_policies, policy_name, None)
         logger.info("MODEL POLICY: handler %s %s" % (policy_name, policy_handler))
         if policy_handler is not None:
             if (deleted):