gpg: Avoid spurious warnings about trust packets.

gpg: Avoid spurious warnings about trust packets.

* g10/keydb.c (parse_keyblock_image): Do not emit a warning when
skipping a trust packet.

--

2.1.20 and later store trust packets in the keybox.  If an older
version (like 2.1.18) ends up accessing a keybox that 2.1.20 or later
has used, it produces many spurious warnings like:

    gpg: skipped packet of type 12 in keybox

This is a temporary cleanup to avoid these specific warnings; it can
be dropped when moving to 2.1.20 or later.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Gbp-Pq: Topic avoid-spurious-warnings
Gbp-Pq: Name 0078-gpg-Avoid-spurious-warnings-about-trust-packets.patch