Fix diffusion browse links in the owner's tool

Summary: ...they were broken...

Test Plan: clicked links for both SVN and Git repos and got working results

Reviewers: vrana, floatinglomas, 20after4

Reviewed By: floatinglomas

CC: aran, epriestley

Maniphest Tasks: T1250

Differential Revision: https://secure.phabricator.com/D2505