Clear "X awarded a token to event Y" stories when visiting event page

Summary: These detail pages don't have a "pageObjects" configuration, so we don't clear, e.g., token stories correctly when users load them.

Test Plan: Will clear a token story in production.

Reviewers: btrahan, lpriestley, chad

Reviewed By: chad

Subscribers: chad, epriestley

Differential Revision: https://secure.phabricator.com/D13582

src/applications/calendar/controller/PhabricatorCalendarEventViewController.php

@@ -105,6 +105,7 @@ public function processRequest() {
       ),
       array(
         'title' => $page_title,
+        'pageObjects' => array($event->getPHID()),
       ));
   }