Removing an unneeded avcodec encoder flush, which was breaking many e…

…ncoders on newer versions of FFMPEG. This would result in failed hardware acceleration and videos with no video frames.

src/FFmpegWriter.cpp

@@ -2233,7 +2233,6 @@ bool FFmpegWriter::write_video_packet(std::shared_ptr<Frame> frame, AVFrame *fra
 				ret = avcodec_receive_packet(video_codec_ctx, pkt);
 
 				if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
-					avcodec_flush_buffers(video_codec_ctx);
 					got_packet_ptr = 0;
 					break;
 				}