message: correct handling of outgoing track stopped event
diff: @@ -72,10 +72,10 @@ class ActiveSpeakerMultiplexer extends Emitter
  for (const [multiplexId,multiplex] of this.multiplex)
  {
  //If same track
  - if (multiplex.track == outgoingTrack)
  + if (multiplex.outgoingTrack == outgoingTrack)
  {
  //Remove from multiplexer
  - this.multiplexer.RemoveRTPStreamTransponder(multiplex.transponder);
  + this.multiplexer.RemoveRTPStreamTransponder(multiplex.transponder.transponder);
  //remove it
  this.multiplex.delete(multiplexId);
  //Done
  @@ -226,6 +226,14 @@ class ActiveSpeakerMultiplexer extends Emitter
  */
  stop()
  {
  + //Don't stop twice
  + if (this.stopped)
  + //Do nothing
  + return;
  +
  + //Stopped
  + this.stopped = true;
  +
  //Stop listening for events, as they might have been queued
  this.onactivespeakerchanged = ()=>{};
  this.onactivespeakerremoved = ()=>{};
  