Style: format code by gofumpt (#761)

proxy/vmess/outbound/outbound.go

@@ -191,7 +191,7 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 		return buf.Copy(bodyReader, output, buf.UpdateActivity(timer))
 	}
 
-	var responseDonePost = task.OnSuccess(responseDone, task.Close(output))
+	responseDonePost := task.OnSuccess(responseDone, task.Close(output))
 	if err := task.Run(ctx, requestDone, responseDonePost); err != nil {
 		return newError("connection ends").Base(err)
 	}