Fix roundtrip loglevel

Author: hons82

server.go

@@ -603,15 +603,18 @@ func (s *Server) listen(l net.Listener, identifier id.ID) {
 func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	resp, err := s.RoundTrip(r)
 	if err != nil {
+		level := 0
 		code := http.StatusBadGateway
 		if err == errUnauthorised {
 			w.Header().Set("WWW-Authenticate", "Basic realm=\"User Visible Realm\"")
+			level = 1
 			code = http.StatusUnauthorized
 		} else if err == errClientNotSubscribed {
+			level = 2
 			code = http.StatusNotFound
 		}
 		s.logger.Log(
-			"level", 0,
+			"level", level,
 			"action", "round trip failed",
 			"addr", r.RemoteAddr,
 			"host", r.Host,