Fix next_uri

Summary: we were using the "path" as the next_uri and that drops some delicious get parameters

Test Plan: see T1140; basically re-ran the steps listed there and they passed!

Reviewers: epriestley, njhartwell

Reviewed By: epriestley

CC: aran, Koolvin

Maniphest Tasks: T1140, T1009

Differential Revision: https://secure.phabricator.com/D2299