[Feature] Hide sign-up link when DISABLE_SIGNUPS: true

[surfingbytes]

Is there an existing issue for this feature?

• Yes, I have searched the existing issues and it doesn't exist.

Feature Description

Currently, when you set DISABLE_SIGNUPS: true, the "Don't have an account? Create one now" is still shown. Error message about it being disabled is shown only after user clicks the link. That is generally bad practice, why is user allowed to click on that link at all? Why is that even shown when user can't use it? I can't imagine any other software showing buttons that you don't have right to click on - e-mail client showing "delete" on e-mails, when you don't have rights in this mailbox, bank showing "send transfer" when you have read-only access to that account. And only after you click on it you get "oh, you actually can't"

Same situation when you set DISABLE_EMAIL_AUTH: true. Check any other software - the login form just disappears and it automatically redirects to configured OPENID provider. Currently, the whole form stays there, blurred, with a message on top. So if you disable e-mail login to make it smoother, you end up with this mess: