Do not try to recover mute state when joining listenonly

Prevent toggleMute api call to be called for listenonly
This has no effect to the end user, but avoids unnecessary server calls

bigbluebutton-html5/imports/ui/components/audio/service.js

@@ -33,7 +33,7 @@ const audioEventHandler = (event) => {
 
   switch (event.name) {
     case 'started':
-      recoverMicState();
+      if (!event.isListenOnly) recoverMicState();
       break;
     default:
       break;

bigbluebutton-html5/imports/ui/services/audio-manager/index.js

@@ -342,7 +342,10 @@ class AudioManager {
       this.notify(this.intl.formatMessage(this.messages.info.JOINED_AUDIO));
       logger.info({ logCode: 'audio_joined' }, 'Audio Joined');
       if (STATS.enabled) this.monitor();
-      this.audioEventHandler({ name: 'started' });
+      this.audioEventHandler({
+        name: 'started',
+        isListenOnly: this.isListenOnly,
+      });
     }
   }