ERR_SERVER_ALREADY_LISTEN

当 net.Server 已经在监听时调用了 server.listen() 方法。这适用于 net.Server 的所有实例，包括 HTTP、HTTPS 和 HTTP/2 Server 实例。

¥The server.listen() method was called while a net.Server was already listening. This applies to all instances of net.Server, including HTTP, HTTPS, and HTTP/2 Server instances.