Bugfix attempt: See if location redirects work

The previous bugfix didn't actually fix the problem, unfortunately. This
time we'll try using "location" instead of "refresh" as the redirect
method, and see if CodeIgniter gets the right URL that way.

It's annoying that we have to push bugfix attempts to master, but the
bug is only manifesting on the dev server (which is behind a reverse
proxy) and not on local VMs which are not behind a reverse proxy. So
this is the only way to test possible fixes.