fix(测试计划): 导出报告看不到关联的缺陷内容

--bug=1011422 --user=李玉号 [BUG]github#11615测试计划执行后，导出报告看不到关联的缺陷内容
https://www.tapd.cn/55049933/s/1122467

Closes #11615

frontend/src/business/components/track/case/components/MsMarkDownText.vue

@@ -112,6 +112,10 @@ export default {
   computed: {
     language() {
       const user = getCurrentUser();
+      // 取值为空时默认中文，如：导出
+      if (!user) {
+        return 'zh_CN';
+      }
       const language = user.language;
       switch (language) {
         case 'zh_CN':

frontend/src/business/components/track/plan/view/comonents/report/detail/component/FunctionalCases.vue

@@ -8,7 +8,7 @@
           :label="$t('commons.id')"
           show-overflow-tooltip>
           <template v-slot:default="{row}">
-            {{isCustomNum ? row.customNum : row.num }}
+            {{row.isCustomNum ? row.customNum : row.num }}
           </template>
         </el-table-column>
         <el-table-column
@@ -92,11 +92,6 @@ export default {
       testCases:  []
     }
   },
-  computed: {
-    isCustomNum() {
-      return this.$store.state.currentProjectIsCustomNum;
-    },
-  },
   mounted() {
     this.getFunctionalTestCase();
   },