fix: 测试用例无法展示关联的缺陷

--bug=1009049 --user=陈建星 【测试跟踪】脑图创建、关联的缺陷，在列表-用例详情里没显示 https://www.tapd.cn/55049933/s/10840777

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

@@ -119,9 +119,9 @@ export default {
       if (this.tabActiveName === 'demand') {
         this.getDemandOptions();
       } else if (this.tabActiveName === 'bug') {
-        if (this.$refs.issue) {
+        this.$nextTick(() => {
           this.$refs.issue.getIssues();
-        }
+        });
       } else if (this.tabActiveName === 'relationship') {
         this.$refs.relationship.open();
       } else if (this.tabActiveName === 'attachment') {