Allow redirecting when not logged in

Summary:
Without this, the https redirect doesn't work if you're not logged in, because
the login check in willBeginExecution happens before the redirect controller
can redirect. This also has the unpleasant effect of the login page on http
(when it should have redirected to https) not having any css or js.

Test Plan:
With the https redirect enabled, loaded phabricator without being logged in,
and saw that I got redirected to the https login page instead of seeing a
http login page.

Reviewers: epriestley, vrana

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D3438