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 is_clcp_track(MOVTrack *track)
{
    return track->tag == MKTAG('c','7','0','8') ||
           track->tag == MKTAG('c','6','0','8');
}

static int is_clcp_track(MOVTrack *track)
{
    return track->tag == MKTAG('c','7','0','8') ||
           track->tag == MKTAG('c','6','0','8');
}
