download from pigeonhole.dovecot.org not possible via IPv6 http

[Wolfgang Zenker]

Hello,

I tried to download the dovecot-2.3-pigeonhole-0.5.15.tar.gz source
archive from
http://pigeonhole.dovecot.org/releases/2.3/dovecot-2.3-pigeonhole-0.5.15.tar.gz on an IPv6-only server, but the download fails.
The server pigeonhole.dovecot.org has an IPv6 address published in DNS
that is actually pingable, but connection on the http-port is not possible.
Connecting on https does work, as does http AND https on IPv4.
This appears to be a simple configuration problem and should be easily
fixed; the correct behaviour would be to redirect from http to https on
IPv6 the same way it is done for IPv4 already.

Greetings,
Wolfgang