a few multiqueue fixes

do not use sharding worker mode
make sure mqids are ints and not strings
set the mq callback before sending the message
delete callbacks afterwards to prevent memory leak

misc/multiqueue.js

@@ -15,7 +15,7 @@ export const useMultiqueue = () => config.useMultiqueue && client.shard && clien
 
 let mqMessageId = 0;
 const callbacks = {};
-const setCallback = (mqid, callback) => callbacks[mqid] = callback;
+const setCallback = (mqid, callback) => callbacks[parseInt(mqid)] = callback;
 
 export const sendMQRequest = async (type, params={}, callback=()=>{}) => {
     const message = {
@@ -25,8 +25,8 @@ export const sendMQRequest = async (type, params={}, callback=()=>{}) => {
         params
     }
 
-    await sendShardMessage(message);
     setCallback(mqMessageId, callback);
+    await sendShardMessage(message);
 }
 
 export const sendMQResponse = async (mqid, params={}) => {
@@ -48,9 +48,15 @@ export const handleMQRequest = async (message) => {
 export const handleMQResponse = async (message) => {
     const [shardId, mqid] = message.mqid.split(":");
 
+    // check the response is intended for this shard
     if(!client.shard.ids.includes(parseInt(shardId))) return;
-    if(!callbacks[mqid]) return;
+
+    // check we have a callback registered
+    if(!callbacks[mqid]) return console.error(`No callback registered for MQ response ${message.mqid}!`);
+
+    // do the thing
     callbacks[mqid](message);
+    delete callbacks[mqid];
 }