结合RxJava发请求，监听文件上传进度，偶现回调进度局部错乱问题

[liujingxing]

RxHttp.postForm("...")
    .addFile("file", File("/.."))
    .upload(AndroidSchedulers.mainThread()) {
        Log.v("tag", "uploadVideo>>${it.progress}") 
    }
    .asResponse<String>()
    .subscribe()