diff -r 60fed6272771 -r e845746b4d3c cubicweb/misc/migration/3.21.2_Any.py
--- a/cubicweb/misc/migration/3.21.2_Any.py	Fri Sep 30 17:36:40 2016 +0200
+++ b/cubicweb/misc/migration/3.21.2_Any.py	Thu Sep 29 11:44:19 2016 +0200
@@ -1,7 +1,1 @@
 sync_schema_props_perms('cwuri')
-
-helper = repo.system_source.dbhelper
-cu = session.cnxset.cu
-helper.set_null_allowed(cu, 'moved_entities', 'extid', 'VARCHAR(256)', False)
-
-commit()