[PATCH] ignore ipv6=off resolver option when no ipv6 support

[Maxim Dounin]

Hello!

On Fri, Dec 16, 2016 at 11:35:44AM -0800, Thibault Charbonnier wrote:

[...]

> Say we wish to disable IPv6 resolution regardless of whether nginx was 
> built with our without support for it:
> 
>      resolver 8.8.8.8 8.8.4.4 ipv6=off;
> 
> Now the issue is that ipv6=off raises this - cryptic to the neophytes - 
> error if nginx was built without IPv6 support:
> 
>      [emerg] host not found in resolver "ipv6=off"

I very much doubt there are any neophytes who try to use nginx on 
operating systems without IPv6 support.  A neophyte most likely 
won't be able to find such OS nowadays.

-- 
Maxim Dounin
http://nginx.org/