[without-ssl-conf.d] Add default.conf without ssl termination option

[a-schaefers]

Summary

Hello, for users who already have SSL termination via some load balancer within a secured VPC, it might be helpful to provide an nginx configuration option for them.

This can be [optionally, not used by default] used by those who desire it, by changing in .env the following var NGINX_CONFIG_PATH=

Original,

NGINX_CONFIG_PATH=./nginx/conf.d

Modified, for those who do not want backend SSL,

NGINX_CONFIG_PATH=./nginx/without-ssl-conf.d

[hanzei]

Thanks for the PR 👍

Can you also please update the README to advertise this new configuration option?