Comment 1 for bug 1705072

E.g.:

I create 3 domains, with the default using sql driver, 2nd using LDAP for ldap_server_1 and 3rd using LDAP for ldap_server_2. I have users in each of those, and some of the users in each of those are setup with default project_id as project foo. When foo gets deleted, I need to update the users in all of those backends to no longer use foo as their default project. Not just the users in the default domain using the sql driver.