Docker container - listen on IPv6

Hi,

There's an issue with the Docker container not listening on IPv6.

The nginx:alpine container that it's based on includes a startup script (10-listen-on-ipv6-by-default.sh) that modifies /etc/nginx/conf.d/default.conf, adding listen [::]:80 to the configuration if IPv6 is available. It will exit if it finds that the default.conf has been modified beforehand.

The omni-tools Dockerfile modifies the default.conf (adding try_files), the IPv6 script sees this change and doesn't make its change to enable IPv6.