eachLimit on expire nids

src/notifications.js

@@ -300,7 +300,7 @@ var async = require('async'),
 					return notif.nid;
 				});
 
-				async.each(expiredNids, function(nid, next) {
+				async.eachLimit(expiredNids, 50, function(nid, next) {
 					async.parallel([
 						function(next) {
 							db.setRemove('notifications', nid, next);