物流助手-查询运单轨迹，getPath，德邦：查询不到轨迹信息

测试环境,addOrder接口下的单:

  getPath返回信息：

object(stdClass)#167 (5) {
  ["openid"] => string(28) "ov5mQ4mIV7BT24IrP7YaPoqHwWJg"
  ["delivery_id"] => string(2) "DB"
  ["waybill_id"] => string(10) "8417642450"
  ["path_item_num"] => int(0)
  ["path_item_list"] => array(0) {
  }
}