obs-ffmpeg: Fix 4 channel layout in ffmpeg-mux

Previously SPEAKER_4POINT0 was assigned to AV_CH_LAYOUT_QUAD, but later
was changed to AV_CH_LAYOUT_4POINT0 [1]. The change was forgotten in
obs-ffmpeg-mux. This is remedied here.
[1] https://github.com/obsproject/obs-studio/commit/67e48ecc2ca033020210f3aae05617195d37e248

Signed-off-by: pkv <[email protected]>

plugins/obs-ffmpeg/ffmpeg-mux/ffmpeg-mux.c

@@ -498,9 +498,6 @@ static void create_audio_stream(struct ffmpeg_mux *ffm, int idx)
 #if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(59, 24, 100)
 	context->channel_layout =
 		av_get_default_channel_layout(context->channels);
-	//avutil default channel layout for 4 channels is 4.0 ; fix for quad
-	if (context->channels == 4)
-		context->channel_layout = av_get_channel_layout("quad");
 	//avutil default channel layout for 5 channels is 5.0 ; fix for 4.1
 	if (context->channels == 5)
 		context->channel_layout = av_get_channel_layout("4.1");