remove extra arg

src/updatechecker.js

@@ -90,7 +90,7 @@ function checkAppUpdates(options, callback) {
                         return callback();
                     }
 
-                    async.eachSeries(admins, (admin, done) => mailer.appUpdatesAvailable(admin.email, notificationPending, true /* subscription */, done), callback);
+                    async.eachSeries(admins, (admin, done) => mailer.appUpdatesAvailable(admin.email, notificationPending, done), callback);
                 });
             });
         });