Incorrect redirect on login

[LeonVreling]

After pushing 0baa3d9, the redirect when pressing the "visit the archive" button is broken. The current button now does a login, and then a redirect either to the main page or the admin page.

Expected behaviour:
When clicking the 'visit the archive' button on the main screen, log in and redirect to the infima archive page. All other logins should keep the current behaviour