[CORD-2826] Removing VSG model import from model_policies

Change-Id: I9f5011a896c07d1f37a2a69434d034ad20f3f814
diff --git a/xos/synchronizer/model_policies/model_policy_voltserviceinstance.py b/xos/synchronizer/model_policies/model_policy_voltserviceinstance.py
index 0255d74..435fbfb 100644
--- a/xos/synchronizer/model_policies/model_policy_voltserviceinstance.py
+++ b/xos/synchronizer/model_policies/model_policy_voltserviceinstance.py
@@ -14,7 +14,7 @@
 # limitations under the License.
 
 
-from synchronizers.new_base.modelaccessor import VOLTServiceInstance, ServiceInstanceLink, VSGService, VSGServiceInstance, model_accessor
+from synchronizers.new_base.modelaccessor import VOLTServiceInstance, ServiceInstanceLink, model_accessor
 from synchronizers.new_base.policy import Policy
 
 class VOLTServiceInstancePolicy(Policy):