i use it, but sync fail

[zxydaisy]

1. 我设置了 remote_registry 和 local_registry
   通过 sinopia 搭建的两个镜像仓库，
   在把 A 仓库的包转移到 B 仓库的时候出错

{
  "error": "wrong content-type, expect: application/json, got: application/json; charset=utf-8"
}

status code is not 201. statusCode: 415
{
  "error": "wrong content-type, expect: application/json, got: application/json; charset=utf-8"
}

Sync has-symbol-support-x, rev: 5-c691eb975f3c7401 fail.
...
{
  "error": "wrong content-type, expect: application/json, got: application/json; charset=utf-8"
}

status code is not 201. statusCode: 415
{
  "error": "wrong content-type, expect: application/json, got: application/json; charset=utf-8"
}

Sync is-plain-obj, rev: 8-20c3b1cee17104b6 fail.

2. 看了一下 https://github.com/JacksonTian/sync_package/blob/master/lib/sync_package.js#L111
   应该是这里报错出来的，我应该怎么设置才不会有编码错误报出来呢？