fix(接口定义): 场景报告时间错误

--bug=1009179 --user=王孝刚 【测试跟踪】jenkin执行测试计划，时间显示异常
https://www.tapd.cn/55049933/s/1086082

backend/src/main/java/io/metersphere/api/service/ApiScenarioReportStructureService.java

@@ -132,8 +132,12 @@ public class ApiScenarioReportStructureService {
                     scenarioError.set((scenarioError.longValue() + 1));
                 }
             } else if (step.getValue() != null) {
+                if (step.getValue().getStartTime() == 0 || step.getValue().getEndTime() == 0) {
+                    totalTime.set(totalTime.longValue() + 0);
+                } else {
                     totalTime.set((totalTime.longValue() + (step.getValue().getEndTime() - step.getValue().getStartTime())));
                 }
+            }
             if (CollectionUtils.isNotEmpty(step.getChildren())) {
                 calculate(step.getChildren(), totalScenario, scenarioError, totalTime);
             }