fix：判断没有学生回答题目的情况；

src/renderer/src/views/classTask/container/classOverview.vue

@@ -218,6 +218,7 @@ const initData = () => {
     return { def: o, id: o.id, type: o.worktype, active: [], points, accSum, rightSum, children,hasAnswers }
   })
   console.log('获取数据: ', data)
+  if (data.length === 0) return
   stuHasAnswers.value = [...data[0].hasAnswers]
   provide('hasAnswer', stuHasAnswers.value)
 }