lavf/movenc: Do not print an error when muxing gray8 rawvideo.

This was fixed in 9a277808

libavformat/movenc.c

@@ -1427,6 +1427,7 @@ static int mov_get_rawvideo_codec_tag(AVFormatContext *s, MOVTrack *track)
                                   track->par->bits_per_coded_sample);
     if (tag == MKTAG('r','a','w',' ') &&
         track->par->format != pix_fmt &&
+        track->par->format != AV_PIX_FMT_GRAY8 &&
         track->par->format != AV_PIX_FMT_NONE)
         av_log(s, AV_LOG_ERROR, "%s rawvideo cannot be written to mov, output file will be unreadable\n",
                av_get_pix_fmt_name(track->par->format));