len(k) is guaranteed to be greater than 1 in this case

util.go

@@ -53,7 +53,7 @@ func FilterCustomQuery(u *nurl.URL) *nurl.URL {
 	ux := *u
 	vx := make(nurl.Values)
 	for k, v := range ux.Query() {
-		if len(k) <= 1 || (len(k) > 1 && k[0:2] != "x-") {
+		if len(k) <= 1 || k[0:2] != "x-" {
 			vx[k] = v
 		}
 	}