dirmngr: Provide the keyserver pool name even if there is no CNAME.
* dirmngr/ks-engine-hkp.c (map_host): Fix setting of r_poolname.
map_host is intended to return the name of the pool as an additional
information. However this broke some time ago and a pool name was
only retrained if the pool name was retrieved from a DNS CNAME.
- Signed-off-by: Werner Koch <wk@gnupg.org>