BUGFIX: User created when user not found

The user used to be created when the mobileaai authentication
failed to authenticate the user and the user was not in the DB.
This commit fixes the issue.

The mobile_aai_auth->user_login function now returns a boolean
value instead of the error structure. The error structure is
stored inside the mobile_aai_auth object and it is accessible
with the mobile_aai_auth->getError function