对性能很差的那种服务器求稳，终极版，适当降低提速效果呗

src/features/ImageDownload/ImageDownload.vue

@@ -362,7 +362,7 @@ const doneTenStudents = () => {
   });
   return new Promise((rs, rj) => {
     const func = (rs: any) => {
-      if (recordManager.curTasksLength <= 5) {
+      if (recordManager.curTasksLength <= 0) {
         //等于-1时，说明离开页面了，需要停止任务。
         cleanTimer();
         rs();