fix(测试跟踪): 编辑用例报错

frontend/src/business/components/track/plan/view/comonents/TestPlanTestCaseEdit.vue

@@ -484,6 +484,7 @@ export default {
         item.issues.hasIssues = false;
       }
       item.steptResults = [];
+      if (item.steps) {
         for (let i = 0; i < item.steps.length; i++) {
           if (item.results[i]) {
             item.steps[i].actualResult = item.results[i].actualResult;
@@ -491,6 +492,7 @@ export default {
           }
           item.steptResults.push(item.steps[i]);
         }
+      }
       this.testCase = item;
       this.initTest();
       this.getIssues(testCase.caseId);