The @superuser_required decorator was passing a dictionary of keyword

arguments, instead of the keyword arguments themselves, to the login()

method. This broke login(), which saw that dictionary as the

template_name argument.
This fixes the code to pass those in as keyword arguments, and fixes the

name of one of the arguments, allowing the view to show a login page

instead of a 500.

Tested visiting as a logged-out user. Saw a login form. Logged in using

it and was taken to the settings page.