Remove shortDigest
Remove shortDigest

The new progress bars forced us to remove almost all users of shortDigest,
the only remaining one is a debug output, where we use the unabbreviated
digests in all other cases.

So, modify the debug output to use the full digest, and drop shortDigest.

Should only change debug output.

Signed-off-by: Miloslav Trmač <9c008e38982a5397deb855345fb164f0558459ae@redhat.com>

containers/image,containers/image