fix: 编辑场景滑动滚动条控制台报错

frontend/src/business/components/api/automation/scenario/EditApiScenario.vue

@@ -1285,6 +1285,7 @@ export default {
     handleScroll() {
       let stepInfo = this.$refs.stepInfo;
       let debugHeader = this.$refs.debugHeader;
+      if (debugHeader) {
         let originWidth = debugHeader.clientWidth;
         if (stepInfo.getBoundingClientRect().top <= 178) {
           this.isTop = true;
@@ -1294,6 +1295,7 @@ export default {
         }
       }
     }
+  }
 }
 </script>