Update RedirectController for handleRequest

Summary: Ref T8628.

Test Plan: Performed an action that uses the redirect controller (trying to visit a repo page while not logged in). Logged in and was redirected as expected

Reviewers: Blessed Reviewers, epriestley

Reviewed By: Blessed Reviewers, epriestley

Subscribers: epriestley, yelirekim

Maniphest Tasks: T8628

Differential Revision: https://secure.phabricator.com/D16571