Remove the hard-coded check for Axelerant in ct_user

[hussainweb]

From #15 (comment)

Since social_google_auth can now restrict the domains, we don't need the check for the email domain in ct_user. The method itself needs to remain as we need to activate the user when they sign up using Google Auth. This feature is not supported by social_auth modules yet. And we can't enable this in Drupal configuration as it will open up registrations through the regular user/register callback.