Add set_real_ip_from working with real_ip_header just like the nginx way

[hnlq715]

http://nginx.org/en/docs/http/ngx_http_realip_module.html

We nedd to define trusted addresses that are known to send correct replacement addresses.

[andrewkroh]

That seems like a good idea.

Are you interested in contributing a pull request for the feature?

[hnlq715]

Thanks for your reply, I will get to this point ASAP