[CORD-1360] migrating metro-net from 3.0 to master, merge with https://gerrit.opencord.org/#/c/4151/

Change-Id: I6d94a88b67ec4862290c1c0538f9cb269c5b76b3
diff --git a/xos/attic/header.py b/xos/attic/header.py
index f4db591..ebda3ac 100644
--- a/xos/attic/header.py
+++ b/xos/attic/header.py
@@ -3,7 +3,7 @@
 from django.db import models
 from django.db.models import *
 from core.models import Service
-from core.models import PlCoreBase
+from core.models import XOSBase
 from core.models import Site
 
 METRONETWORK_KIND = "metronetwork"