Post metrics twice when tranfer data to server

[erjinzhi2333]

Here is my cfg.json
{ "debug": false, "attachtags": "", "http": { "enable": false, "listen": "0.0.0.0:1987" }, "transfer": { "enable": true, "addr": "http://127.0.0.1:8433", "interval": 3, "timeout": 1000 } }
127.0.0.1:8433 is a server that handle lvs-metrics data
I will get two request every tranfer，one is the collect data and another get 0 for all metrics.
Like this：
[{"endpoint":"localhost.localdomain","metric":"lvs.vip.inpkts","value":338884,"step":3,"counterType":"COUNTER","tags":"vip=192.168.65.11,port=80","timestamp":1536128359}]

[{"endpoint":"localhost.localdomain","metric":"lvs.in.packets","value":0,"step":3,"counterType":"GAUGE","tags":"","timestamp":1536128359}]