Don't show "View Wiki" reminder link if viewer has no access to Phriction

Summary: Fixes T6581.

Test Plan:
  - Loaded project page with Phriction accessible, saw link.
  - Loaded project page with Phriction uninstalled, no link.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T6581

Differential Revision: https://secure.phabricator.com/D10868

src/applications/project/controller/PhabricatorProjectProfileController.php

@@ -261,12 +261,17 @@ final class PhabricatorProjectProfileController
       }
     }
 
+    $have_phriction = PhabricatorApplication::isClassInstalledForViewer(
+      'PhabricatorPhrictionApplication',
+      $viewer);
+    if ($have_phriction) {
       $view->addAction(
         id(new PhabricatorActionView())
           ->setIcon('fa-book grey')
           ->setName(pht('View Wiki'))
           ->setWorkflow(true)
           ->setHref('/project/wiki/'));
+    }
 
     return $view;
   }