Fix a issue with Google Chrome

relay.go

@@ -255,7 +255,14 @@ func newCall(mainOffer receivedSignal, r activeRelay) {
 		}()
 
 		// Create a local track, all our SFU clients will be fed via this track
-		localTrack, newTrackErr := mainPeerConnection.NewTrack(remoteTrack.PayloadType(), remoteTrack.SSRC(), remoteTrack.ID(), remoteTrack.Label())
+		trackID := "audio"
+		trackLabel := "pion" // We need only one track label
+		if remoteTrack.Kind() == webrtc.RTPCodecTypeVideo {
+			trackID = "video" // We need two different track ids
+		}
+
+		localTrack, newTrackErr := mainPeerConnection.NewTrack(remoteTrack.PayloadType(), remoteTrack.SSRC(), trackID, trackLabel)
+
 		if newTrackErr != nil {
 			log.Println("New track error!", err)
 			askForClose(r)