长时间无请求时，anyproxy卡住，只能手工ctrl+c 下请求才接收到之前的请求

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ie配置的代理，anyproxy 长时间没接收到请求 或 运行时间较长时，anyprox经常卡住，接收不到转发的内容。手工ctrl+c，会立即将之前请求信息打印出来。

#### Which platform are you running AnyProxy

操作系统：windows10

#### The version of the AnyProxy

anyproxy: 4.0.12
node: 8.12.0

#### Your expected behavior of AnyProxy

实时响应，不会卡住

#### The actual behavior of AnyProxy

#### The log of the error

Reproduce the hang on Windows 10 with AnyProxy 4.0.12 and Node 8.12.0, using a long idle period or extended runtime before sending a request. Trace the request handling and logging entry points to determine why Ctrl+C releases the earlier request; done means requests are handled and logged in real time without manual interruption.

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