dirmngr: Ask keyservers to provide the key fingerprints
* dirmngr/ks-engine-hkp.c (ks_hkp_search): Add "fingerprint=on" to request URL.
Some keyservers, e.g. keyserver.ubuntu.com (Hockeypuck), do not
provide the key fingerprints by default. Therefore, we ask for the
fingerprints explicitly.
- GnuPG-bug-id: T5741