message: SocketHandle should be removed from iface when connection closed
diff: @@ -56,8 +56,7 @@ struct TcpConnection {
  impl Drop for TcpConnection {
  fn drop(&mut self) {
  let mut manager = self.manager.lock();
  - let socket = manager.iface.get_socket::<TcpSocket>(self.socket_handle);
  - socket.close();
  + manager.iface.remove_socket(self.socket_handle);
  }
  }
  