This fixes ModernBB/Luna#922

Fixes the problem that if the admin group are saved they obtain moderator privileges. Which leads to problems for example in [profile-admin.tpl.php](https://github.com/xf17/Luna/blob/version3.5/style/Core/templates/views/profile-admin.tpl.php#L19-L37).
 `g_moderator` should be '0' for Admins.
If I'm not mistaken.