caddyhttp: reverseproxy: clarify warning for -insecure (#4379)
caddyhttp: reverseproxy: clarify warning for -insecure (#4379)

The question would only receive bad answers so it's better
to just say what the option actually does.
mholt/caddy,l3dlp/caddy,l3dlp/caddy,l3dlp/caddy,mholt/caddy