qtmux: need remove moov track when release pad

Below code in gst_qt_mux_request_new_pad() will add track in moov. But don't remove it in gst_qt_mux_release_pad(). Our video encoder don't support one preset. it will call request pad and then release pad for the first try. But the output mp4 file can't be playback as below code. Do we need remove moov track in release pad function or need put below code in other function to delay add moov track?

qtpad->trak = atom_trak_new (qtmux->context);

atom_moov_add_trak (qtmux->moov, qtpad->trak);