Fix redirect to Password settings panel after "Reset Password" login

Summary: Fixes T11107. The URI change here meant we were dropping the "key" parameter, which allows you to set a new password without knowing your old one.

Test Plan: Reset password, didn't need to provide old one anymore.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T11107

Differential Revision: https://secure.phabricator.com/D16075