CI: Resurrect keys.n3npq.net SKS keyserver

[Jeff Johnson]

RPM's automatecd testing needs a functioning
    hkp://keys.n3npq.net
SKS keyserver running.

(barnstable.jbj.org == keys.n3npq.net)

The SKS key server has been restarted on barnstable and is actively syncing.
If/when keys.n3npq.net rejoins the active pool here
    http://sks-keyservers.net/status/
or (specific status)
    http://keys.n3npq.net:11371/pks/lookup?op=stats
then the hkp:// retrievals in "make test" need to be re-enabled.

[Jeff Johnson (n3npq)]

The keys.n3npq.net server is now synced. The last remaining piece
si to re-enable the hkp:// retrieval tests in rpm-5.4.6.

[Jeff Johnson (n3npq)]

Both "keys.n3npq.net" and "keys.jbj.org" are active in the SKS key server
pools here
    http://sks-keyservers.net/status/

Still without IPv6 (and index.html pages) support, but I'll tweak that in soon.