fix handle proxy request in http relay

[V-E-O]

if client requests with absolute uri: GET http://www.github.com HTTP/1.1 Host: www.github.com

tcp-relay will redirect it as: GET http://http://www.github.com HTTP/1.1 Host: www.github.com

[V-E-O]

https://tools.ietf.org/html/rfc2616#section-5.1.2

5.1.2 Request-URI

The Request-URI is a Uniform Resource Identifier (section 3.2) and identifies the resource upon which to apply the request.

   Request-URI    = "*" | absoluteURI | abs_path | authority

[darkk]

That's correct, but IMHO http-relay should be avoided as it's can of bugs. Why do you use it?

• it does not support keep-alive (it modifies only the first request)
• it is workaround for HTTP/1.0 client that does not send any Host header
• it is vulnerable to CVE-2009-0801 as original destination IP address is lost, upstream proxy does not know it, and it has to trust Host header that can be manipulated