Fix headers_js

connect/headers_js.go

@@ -5,6 +5,6 @@ package connect
 import "net/http"
 
 func (wc *webConn) addHeaders(header http.Header) http.Header {
-	req.Header.Add("js.fetch:mode", "no-cors")
+	header.Add("js.fetch:mode", "no-cors")
 	return header
 }