fix(editReportingData): 修复删除报关数据行后重新添加的问题

- 修复删除最后一行报关数据后重新添加时，序号计算错误的问题
-增加判断，避免删除第一行数据时出现错误

@@ -870,7 +870,8 @@
         this.$router.go(-1);
       },
       addNewItem() {
-          let orderNum = this.detailData.at(-1).gnum + 1
+        console.log(this.detailData.at(-1))
+          let orderNum = this.detailData.at(-1) === undefined ?  1 : this.detailData.at(-1).gnum + 1
           this.detailData.push({
             "gnum":orderNum,
             "accountBookMaterialNumber": "",
@@ -943,7 +944,9 @@
       },
       cancelEditRowData(index){
         this.expandRowKeys = []
-        this.detailData.splice(index)
+        if(index!==0){
+          this.detailData.splice(index)
+        }
       },
 
       //提交更新数据