from branch v2: fix: invalid memory address or nil pointer dereferenc…

…e in response logger (#872)

Co-authored-by: Martin Jöhren <m.joehren@gmail.com>

middleware.go

@@ -371,7 +371,7 @@ func responseDebugLogger(c *Client, res *Response) error {
 	debugLog := res.Request.values[debugRequestLogKey].(string)
 	debugLog += "~~~ RESPONSE ~~~\n" +
 		fmt.Sprintf("STATUS       : %s\n", res.Status()) +
-		fmt.Sprintf("PROTO        : %s\n", res.RawResponse.Proto) +
+		fmt.Sprintf("PROTO        : %s\n", res.Proto()) +
 		fmt.Sprintf("RECEIVED AT  : %v\n", res.ReceivedAt().Format(time.RFC3339Nano)) +
 		fmt.Sprintf("TIME DURATION: %v\n", res.Time()) +
 		"HEADERS      :\n" +