ruby sdk 有时调用 `pusher.push` 方法时报错 `end of file reached`

环境：
ruby 2.3.4p301
jpush (4.0.8)

参考文档的写法

app_key = 'xxx'
master_secret = 'xxx'
jpush = JPush::Client.new(app_key, master_secret)

# Push API
pusher = jpush.pusher

# simplest push Hello to all
push_payload = JPush::Push::PushPayload.new(
  platform: 'all',
  audience: 'all',
  notification: 'hello jpush',
  message: 'hello world'
)
pusher.push(push_payload)

网上说是 https 的问题，但我看源码是有设置的，应该不是 https 的问题