Fix lose SSL Passthrough
* [Authentication](#authentication)
* [Rewrite](#rewrite)
* [Rate limiting](#rate-limiting)
+* [SSL Passthrough](#ssl-passthrough)
* [Secure backends](#secure-backends)
* [Server-side HTTPS enforcement through redirect](#server-side-https-enforcement-through-redirect)
* [Whitelist source range](#whitelist-source-range)
