Fix the bug with adding users

Adding a user who already has an email address in CC fails with a generic error message that the email is already in use (when, in fact, it is not in use).

Management of users in CC is a pain. Please fix this so I can add whoeverm whenever, with whatever email address I want. It shouldn't matter if they have 1 CC account under that email or 100.

Love to see this bug quashed.