Fix auth

Created by: zzet

Permit fields for auth from login form: https://github.com/gitlabhq/gitlabhq/blob/master/app/views/devise/sessions/_new_base.html.haml#L2-L3 https://github.com/gitlabhq/gitlabhq/blob/master/app/views/devise/sessions/_new_base.html.haml#L7