[SEBA-218] Making ONU serial number handling case insensitive

Change-Id: I7cd42041709c5e8041959da84c7e1853a8ba0636
diff --git a/xos/synchronizer/model_policies/model_policy_att_workflow_driver_whitelistentry.py b/xos/synchronizer/model_policies/model_policy_att_workflow_driver_whitelistentry.py
index c38e7ec..c788d23 100644
--- a/xos/synchronizer/model_policies/model_policy_att_workflow_driver_whitelistentry.py
+++ b/xos/synchronizer/model_policies/model_policy_att_workflow_driver_whitelistentry.py
@@ -26,10 +26,19 @@
     def handle_update(self, whitelist):
         self.logger.debug("MODEL_POLICY: handle_update for AttWorkflowDriverWhiteListEntry", whitelist=whitelist)
 
-        sis = AttWorkflowDriverServiceInstance.objects.filter(serial_number = whitelist.serial_number,
-                                                   owner_id = whitelist.owner.id)
+        # TODO is Django construct '__iexact' available here?
+        # sis = AttWorkflowDriverServiceInstance.objects.filter(
+        #     serial_number = whitelist.serial_number,
+        #     owner_id = whitelist.owner.id)
+
+        sis = AttWorkflowDriverServiceInstance.objects.all()
 
         for si in sis:
+
+            if si.serial_number.lower() != whitelist.serial_number.lower():
+                # NOTE we don't care about this SI as it has a different serial number
+                continue
+
             if si.valid != "valid":
                 self.logger.debug("MODEL_POLICY: activating AttWorkflowDriverServiceInstance because of change in the whitelist", si=si)
                 si.valid = "valid"