Update admin.py
Update admin.py

Adding user_name to superuser/CM view on errata edit page. I also removed the user_email view from the else: statement.

Connexions/openstax-cms,Connexions/openstax-cms,openstax/openstax-cms,openstax/openstax-cms,openstax/openstax-cms,openstax/openstax-cms