avformat/movenc: Write version 2 of audio atom if channels is not known

The version 1 needs the channel count and would divide by 0
Fixes: division by 0
Fixes: fpe_movenc.c_1108_1.ogg
Fixes: fpe_movenc.c_1108_2.ogg
Fixes: fpe_movenc.c_1108_3.wav

Found-by: #CHEN HONGXU# <HCHEN017@e.ntu.edu.sg>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
static int mov_write_tfdt_tag(AVIOContext *pb, MOVTrack *track)
{
    int64_t pos = avio_tell(pb);

    avio_wb32(pb, 0); /* size */
    ffio_wfourcc(pb, "tfdt");
    avio_w8(pb, 1); /* version */
    avio_wb24(pb, 0);
    avio_wb64(pb, track->frag_start);
    return update_size(pb, pos);
}

static int mov_write_tfdt_tag(AVIOContext *pb, MOVTrack *track)
{
    int64_t pos = avio_tell(pb);

    avio_wb32(pb, 0); /* size */
    ffio_wfourcc(pb, "tfdt");
    avio_w8(pb, 1); /* version */
    avio_wb24(pb, 0);
    avio_wb64(pb, track->frag_start);
    return update_size(pb, pos);
}
