sslutil: make cert fingerprints messages more actionable The previous warning and abort messages were difficult to understand. This patch makes them slightly better. I think there is still room to tweak the messaging. And as we adopt new security defaults, these messages will certainly change again. But at least this takes us a step in the right direction. References to "section" have been removed because if no fingerprint is defined, "section" can never be "hostfingerprints." So just print "hostsecurity" every time.