Fix load_superuser to work with new oslo

If an existing User needs to be updated, it may be done using
'load_superusers'

Change-Id: I12266587fe768a9cc1b07c261680261b172472d8
Adding creator_id field assignment

current_user_id is used as a creator_id

Change-Id: I42778d0e5bbb29a4f7a5b45df275847acc99edf6
Merge "Fix load_superuser to work with new oslo"