alac: Reject rice_limit 0 if compression is used

If in compression mode rice_limit = 0 leads to call
`show_bits(gb, k)` in `decode_scalar` with k = 0.

Request a sample in case it is valid and it should be accepted.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

CC: libav-stable@libav.org
