@julian thanks for your reply. I will try to apply your PR directly and see the result.
After successful registration/login plugin will redirect to domain:4567/forum, instead on domain/forum for what ive created proxy pass.
So im using fb login on url domain/forum/login and after i used it i get redirected to domain:4567/forum.
Now when i disabled 4567 port in firewall i cant use plugin anymore.