core: Return a better error code on certain decryption failures.
* src/decrypt.c (op_data_t): Add field first_status_error. (parse_status_error): Set it. (_gpgme_decrypt_status_handler): Prefer an ERROR code over a NO_SECKEY.
- GnuPG-bug-id: T3983
- Signed-off-by: Werner Koch <wk@gnupg.org>