fix: 作业分数显示修改

learnOnline/apiService/CourseApi.js

@@ -164,7 +164,7 @@ const getCourseAssess = (cid, sid, callback) => {
           tempArr.push({
             name: __.title,
             created_time: __.created_time || '暂未提交',
-            score: __.score || '0'
+            score: __.score === null ? '暂无' : __.score
           })
         }
         homewrok.push({