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 co64_required(const MOVTrack *track)
{
    if (track->entry > 0 && track->cluster[track->entry - 1].pos + track->data_offset > UINT32_MAX)
        return 1;
    return 0;
}

static int co64_required(const MOVTrack *track)
{
    if (track->entry > 0 && track->cluster[track->entry - 1].pos + track->data_offset > UINT32_MAX)
        return 1;
    return 0;
}
