Fixes #6261

If a connection to the parent process is not detected, disable
the restart and reload buttons (as they won't work anyway).

src/controllers/admin/dashboard.js

@@ -48,6 +48,7 @@ dashboardController.get = function (req, res, next) {
 				version: nconf.get('version'),
 				notices: results.notices,
 				stats: results.stats,
+				canRestart: !!process.send,
 			});
 		},
 	], next);