Convert setCaption() to safe HTML

Test Plan: /settings/panel/display/

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2432

Differential Revision: https://secure.phabricator.com/D4824

src/applications/directory/controller/PhabricatorDirectoryMainController.php

@@ -149,9 +149,9 @@ final class PhabricatorDirectoryMainController
 
     $panel = new AphrontPanelView();
     $panel->setHeader('Needs Triage');
-    $panel->setCaption(
+    $panel->setCaption(hsprintf(
       'Open tasks with "Needs Triage" priority in '.
-      '<a href="/project/">projects you are a member of</a>.');
+      '<a href="/project/">projects you are a member of</a>.'));
 
     $panel->addButton(
       phutil_tag(