nginx mail proxy - dovecot ssl backend

[dukzcry]

Now, here is the minimal patch:
https://raw.github.com/druga/aeriebsd-tree/master/usr.sbin/nginx/patch-nginx_mail_proxy_ssl_backends.diff
I do provide neither hostnames nor starttls support in it, because the code
for their support is too much invasive :-(

P.S.: The patch isn't good enough to be included into nginx. So if anybody
is going to fix it, you're welcome.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,219069,247910#msg-247910