make-webcerts: improve dns name recognition and increase key size

old system kept coming up with (none) as the dns name.

new system

increased key size to 2048 to further annoy the NSA.
redir.sh - ipv6 servername is already in []

putting it in [] twice doesn't work.
lighttpd: admin interface for ipv6 did not https listen on ipv6

for https://[my:ip:v6::addr]:81 urls.

Discovered by creating a he tunnel without firewall rules.