Caddy shows "ResponseWriter doesn't implement http.Flusher" when enable access log and connect to a proxy server using HTTP/2 about forwardproxy HOT 4 OPEN

--- old/forwardproxy/forwardproxy.go	2023-08-18 16:29:35.315551349 +0800
+++ new/forwardproxy/forwardproxy.go	2023-08-18 16:27:56.808116573 +0800
@@ -309,13 +309,12 @@ func (h *Handler) ServeHTTP(w http.Respo
 			fallthrough
 		case 3:
 			defer r.Body.Close()
-			wFlusher, ok := w.(http.Flusher)
-			if !ok {
-				return caddyhttp.Error(http.StatusInternalServerError,
-					fmt.Errorf("ResponseWriter doesn't implement http.Flusher"))
-			}
+			wController := http.NewResponseController(w)
 			w.WriteHeader(http.StatusOK)
-			wFlusher.Flush()
+			err := wController.Flush()
+			if err != nil {
+				return caddyhttp.Error(http.StatusInternalServerError, fmt.Errorf(err.Error()))
+			}
 			return dualStream(targetConn, r.Body, w)
 		}