Issue Description

ExtractIPFromRealIPHeader does not return what was found in x-real-ip

func ExtractIPFromRealIPHeader(options ...TrustOption) IPExtractor {	checker := newIPChecker(options)	return func(req *http.Request) string {	directIP := ExtractIPDirect()(req)	realIP := req.Header.Get(HeaderXRealIP)	if realIP != "" {	if ip := net.ParseIP(directIP); ip != nil && checker.trust(ip) {	return realIP	}	}	return directIP	} } 

if realIP != "" should be if realIP == ""
because ultimately the logic that exists now is when you have real and direct ip it will return direct and not real

Checklist

• [ x] Dependencies installed
• [ x] No typos
• [ x] Searched existing issues and docs

Expected behaviour

when x-real-ip is present the IPExtractor should return that ip instead of the directIP from RemoteAddr

Actual behaviour

ExtractIPFromRealIPHeader returns RemoteAddr if both RemoteAddr and x-real-ip exist

Steps to reproduce

Working code to debug

package main func main() { }

Version/commit