caddyhttp: Optionally use forwarded IP for remote_ip matcher
caddyhttp: Optionally use forwarded IP for remote_ip matcher

The remote_ip matcher was reading the X-Forwarded-For header by default, but this behavior was not documented in anything that was released. This is also a less secure default, as it is trivially easy to spoof request headers. Reading IPs from that header should be optional, and it should not be the default.

This is technically a breaking change, but anyone relying on the undocumented behavior was just doing so by coincidence/luck up to this point since it was never in any released documentation. We'll still add a mention in the release notes about this.

l3dlp/caddy,l3dlp/caddy,mholt/caddy,mholt/caddy,l3dlp/caddy