gpg: Improve verbose output during import.

* g10/import.c (chk_self_sigs): Print the subkeyid in addition to the
keyid.
(delete_inv_parts): Ditto.

(cherry picked from commit 1bc6b5174248ba4d83d648ef6d6f4550540d1f20)

• Signed-off-by: Werner Koch <wk@gnupg.org>