分配两千多个客户，成功一千七百多个，后面的都返回40099错误。

但是过一会再分配，又可以成功。

corpid:  ww27f158d9319a7e2b
2020-09-30 10:34:59.516
请求参数：{"handover_userid":"FuZiLin01","takeover_userid":"FuZiLin","external_userid":"wm6_UVDwAAZzYaI9bBNYp43G0rC6tTsQ","retry":0}
返回：{"errcode":40099,"errmsg":"external contact reach limit, hint: [1601433299_100_255ed027b1681a2e9f70bc4d52da9755], from ip: 120.25.167.86, more info at https://open.work.weixin.qq.com/devtool/query?e=40099"}

2020-09-30 14:19:22.453
请求参数：{"handover_userid":"FuZiLin01","takeover_userid":"FuZiLin","external_userid":"wm6_UVDwAAByzYlkQaPV7znLymjC8lgw","retry":0}
返回：{"errcode":0,"errmsg":"ok"}