fix(测试跟踪): 关联需求缺少other选项

--bug=1023703 --user=陈建星 【测试跟踪】功能用例编辑页面，关联需求，不展示默认的other需求了 https://www.tapd.cn/55049933/s/1341502

test-track/frontend/src/business/case/components/case/CaseBaseInfo.vue

@@ -629,18 +629,21 @@ export default {
         issueDemandList(this.projectId)
           .then((r) => {
             this.demandOptions = [];
-            this.demandList = r.data;
+            if (r.data) {
+              this.demandList = r.data;
+            }
             this.buildDemandOptions();
           })
-          .catch(() => {
+          .catch((r) => {
+            this.demandOptions = [];
             this.addOtherOption();
           });
       }
     },
     buildDemandOptions() {
       this.demandOptions = [];
+      this.addOtherOption();
       if (this.demandList.length > 0) {
-        this.addOtherOption();
         this.buildDemandCascaderOptions(this.demandList, this.demandOptions, []);
       }
     },