find out from where non-nicknym keys are discovered

bitmask is encrypting for address that don't send openpgp header neither send attached key. AFAIK the keys are not discovered by the client, I guess they come from the nicknym server. Are the validation levels correctly setted for this situation?

(from redmine: created on 2015-02-09, closed on 2015-03-30, relates #6815 (closed))