Redirect after post when changing Diffusion view

Summary: I spend most time in software development by being lazy.

Test Plan: Changed view, reloaded page, viewed the file without sending the form.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D3012

src/applications/diffusion/controller/DiffusionBrowseFileController.php

@@ -43,6 +43,9 @@ final class DiffusionBrowseFileController extends DiffusionController {
         PhabricatorUserPreferences::PREFERENCE_DIFFUSION_VIEW,
         $selected);
       $preferences->save();
+
+      return id(new AphrontRedirectResponse())
+        ->setURI($request->getRequestURI()->alter('view', $selected));
     }
 
     $needs_blame = ($selected == 'blame' || $selected == 'plainblame');