gpg: Allow importing keys with duplicated long key ids.
* g10/keydb.c (keydb_handle): Add field no_caching. (keyblock_cache): Repalce field kid by fpr. (keydb_disable_caching): New. (keydb_search): Use the fingerprint as cache index. * g10/import.c (import_one): Use the fingerprint and not the kid to lookup the key. Call keydb_disable_caching beofre re-searching for update. * tests/openpgp/import.test: Add a test case.
- Signed-off-by: Werner Koch <wk@gnupg.org>