[entities] fetch_order -> cw_fetch_order

entities.py

@@ -11,7 +11,7 @@ from cubicweb.entities import AnyEntity, fetch_config
 class Person(AnyEntity):
     """customized class for Person entities"""
     __regid__ = 'Person'
-    fetch_attrs, fetch_order = fetch_config(['surname', 'firstname'])
+    fetch_attrs, cw_fetch_order = fetch_config(['surname', 'firstname'])
     rest_attr = 'surname'
     skip_copy_for = ('primary_email',)