* keydb.c (keydb_insert_cert): Do not lock here, but only check if
it is locked.
(keydb_store_cert): Lock here.
* keydb.h (keydb_delete): Accept new argument UNLOCK.
* keydb.c (keydb_delete): Likewise. Only unlock if this is set.
* delete.c (delete_one): Add new argument to invocation of
keydb_delete.