fix(VoiceConnection): use Speaking#has to fire _stoppedSpeaking (#2896)

* Use match on speaking bitmask to fire _stoppedSpeaking

* Use constants and correct matching

* Correctly do a not check

src/client/voice/VoiceConnection.js

@@ -447,12 +447,12 @@ class VoiceConnection extends EventEmitter {
      */
     if (this.status === VoiceStatus.CONNECTED) {
       this.emit('speaking', user, speaking);
-      if (!speaking) {
+      if (!speaking.has(Speaking.FLAGS.SPEAKING)) {
         this.receiver.packets._stoppedSpeaking(user_id);
       }
     }
 
-    if (guild && user && old !== speaking) {
+    if (guild && user && !old.equals(speaking)) {
       const member = guild.member(user);
       if (member) {
         /**