dirmngr: Stricter handling of http error codes.
* dirmngr/ks-action.c (ks_action_search): Only retry if the keyserver
responded with a '404 Not Found'.
* dirmngr/ks-engine-hkp.c (send_request): Return http status code.
(ks_hkp_search): Likewise.
(ks_hkp_{get,put}): Adapt call to 'send_request'.
* dirmngr/ks-engine.h (ks_hkp_search): Update prototype.- Signed-off-by: Justus Winter <justus@g10code.com>