The name is what the user is putting in DNS. server_name has to match or SNI falls
through to another vhost on the same socket.
Addresses are unchanged: 172.21.91.140 and fd3c:3f9b:6424:2::5, still sharing 443
under the existing *.mckero.dn42 wildcard.
Verified after reload: 200 on both families with the certificate validating, 80
redirecting, and dns./mail. still 200. This time nginx -t ran after the symlink was
in place, which is the ordering that caught me out last time.
