fix(addClassDialog): 修复异常重试时的返回值逻辑

修正catch块中多余的return语句，确保异步重试逻辑正确执行

src/components/dialog/addClassDialog.vue

@@ -223,8 +223,8 @@
         }
       } catch (e) {
         console.log(e);
-        setTimeout(()=>{
-          return syncClassData2(classData);
+        return setTimeout(()=>{
+          syncClassData2(classData);
         },10000);
       }