[SEBA-164] Forcing subscriber auth if onu goes down

Change-Id: I6d1b721ac67533fb2b58048666771b50d3a84b2b
diff --git a/xos/synchronizer/steps/sync_att_workflow_driver_service_instance.py b/xos/synchronizer/steps/sync_att_workflow_driver_service_instance.py
index 0b9546b..6923062 100644
--- a/xos/synchronizer/steps/sync_att_workflow_driver_service_instance.py
+++ b/xos/synchronizer/steps/sync_att_workflow_driver_service_instance.py
@@ -40,6 +40,8 @@
             return False
 
         whitelisted = matching_entries[0]
+
+        # FIXME if the ONU is not there yet it raise an index error, if that happens raise DeferredException
         pon_port = ONUDevice.objects.get(serial_number=si.serial_number).pon_port
         if pon_port.port_no != whitelisted.pon_port_id or si.of_dpid != whitelisted.device_id:
             log.warn("ONU disable as location don't match", object=str(si), serial_number=si.serial_number,