ngx_listening_t API change

[Ruslan Ermilov]

Hi,

The ipv6only field of the ngx_listening_t structure was changed to
accept only 0 or 1 to mean turn IPV6_V6ONLY off or on, respectively.
The old semantics of 0 (leave IPV6_V6ONLY at OS default) is no longer
supported.

3rd party modules that create their own listening sockets might need
fixing.  At least the following modules (authors Cc:ed) are known to
be affected by this change: rtmp, tcp proxy.

Please see the following commit for details:
http://trac.nginx.org/nginx/changeset/4772/nginx