gpg: accept subkeys with a good revocation but no self-sig during import

gpg: accept subkeys with a good revocation but no self-sig during import

* g10/import.c (chk_self_sigs): Set the NODE_GOOD_SELFSIG flag when we
encounter a valid revocation signature. This allows import of subkey
revocation signatures, even in the absence of a corresponding subkey
binding signature.

--

This fixes the remaining test in import-incomplete.scm.

GnuPG-Bug-id: 4393
Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Gbp-Pq: Topic import-merge-without-userid
Gbp-Pq: Name gpg-accept-subkeys-with-a-good-revocation-but-no-self-sig.patch