Use AphrontFormLayoutView, not AphrontFormView, for GitHub 'Repository'

interface

Summary:
See T58. When I originally wrote this interface you couldn't make a form that
looked like a form but wasn't really a form, so I made it a real form. That
meant you could hit "return" in the text input and submit the form, which didn't
do anything but is vaguely silly.

After D422 there's a layout-only form element, so switch to that.

Test Plan: Loaded the tab, hit return in the textarea, it didn't do a form
submit.
Reviewed By: jungejason
Reviewers: jungejason, tuomaspelkonen, aran
CC: aran, jungejason, epriestley
Differential Revision: 719

src/applications/repository/controller/edit/PhabricatorRepositoryEditController.php

@@ -508,7 +508,6 @@ class PhabricatorRepositoryEditController
 
   private function processGithubRequest() {
     $request = $this->getRequest();
-    $user = $request->getUser();
     $repository = $this->repository;
     $repository_id = $repository->getID();
 
@@ -516,9 +515,10 @@ class PhabricatorRepositoryEditController
     $path = '/github-post-receive/'.$repository_id.'/'.$token.'/';
     $post_uri = PhabricatorEnv::getURI($path);
 
-    $gitform = new AphrontFormView();
+    $gitform = new AphrontFormLayoutView();
     $gitform
-      ->setUser($user)
+      ->setBackgroundShading(true)
+      ->setPadded(true)
       ->appendChild(
         '<p class="aphront-form-instructions">You can configure GitHub to '.
         'notify Phabricator after changes are pushed. Log into GitHub, go '.

src/applications/repository/controller/edit/__init__.php

@@ -22,6 +22,7 @@ phutil_require_module('phabricator', 'view/form/control/submit');
 phutil_require_module('phabricator', 'view/form/control/text');
 phutil_require_module('phabricator', 'view/form/control/textarea');
 phutil_require_module('phabricator', 'view/form/error');
+phutil_require_module('phabricator', 'view/form/layout');
 phutil_require_module('phabricator', 'view/layout/panel');
 phutil_require_module('phabricator', 'view/layout/sidenav');
 phutil_require_module('phabricator', 'view/utils');