User e-mail change
How do we handle an e-mail change of a user? (Marriage, changed e-mail provider, etc)
Well, the old e-mail will always remain for login, as it is the UID in fairlogin. This is acceptable for users.
Until 2020 it was possible that a user could change his/her delivery e-mail in keycloak. This is not possible anymore, keycloak throws an error.
May be related to https://issues.redhat.com/browse/KEYCLOAK-11715