Allow lines which start with either a 40- or 64-character hex object ID,
to allow for both SHA-1 and SHA-256.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>