Shorten final certificate issuance log line. (#4861)
Shorten final certificate issuance log line. (#4861)

Previously, we logged both the precertificate and the final certificate
when the final certificate was signed. However, we already log the
precertificate body at precertificate issuance time, and we can conect
the two log lines by serial, so this was making the final certificate
log line unnecessarily long.
letsencrypt/boulder,jsha/boulder,bmw/boulder,jcjones/boulder,jcjones/boulder,jsha/boulder,jsha/boulder,letsencrypt/boulder,bmw/boulder,jcjones/boulder,jcjones/boulder,bmw/boulder,letsencrypt/boulder