fix CreateAudioSource when source type is kCustom (#120)

Co-authored-by: CloudWebRTC <[email protected]>

Author: gutjei

src/rtc_peerconnection_factory_impl.cc

@@ -206,7 +206,7 @@ scoped_refptr<RTCAudioSource> RTCPeerConnectionFactoryImpl::CreateAudioSource(
     const string audio_source_label, RTCAudioSource::SourceType source_type) {
   auto options = webrtc::AudioOptions();
   webrtc::scoped_refptr<libwebrtc::LocalAudioSource> rtc_source_track =
-      CreateAudioSourceWithOptions(&options);
+      CreateAudioSourceWithOptions(&options, source_type == RTCAudioSource::SourceType::kCustom);
   scoped_refptr<RTCAudioSourceImpl> source = scoped_refptr<RTCAudioSourceImpl>(
       new RefCountedObject<RTCAudioSourceImpl>(rtc_source_track, source_type));
   return source;