https://developers.weixin.qq.com/doc/offiaccount/Message_Management/Receiving_event_pushes.html

用户扫描带参数二维码关注时，微信公众平台没有返回对应的ticket，具体返回信息如下

<xml>
 <ToUserName><![CDATA[gh_3c9b10438888]]></ToUserName>
 <FromUserName><![CDATA[ogOpsuAmOuYmjYTkP69Xuc8I8GSM]]></FromUserName>
 <CreateTime>1595400083</CreateTime>
 <MsgType><![CDATA[event]]></MsgType>
 <Event><![CDATA[subscribe]]></Event>
 <EventKey><![CDATA[qrscene_10000004]]></EventKey>
</xml>