:meth:`.WNetworkNativeTransportProto.close_server_socket` method implementation

def close_server_socket(self, config, close_fd=True):
		""" :meth:`.WNetworkNativeTransportProto.close_server_socket` method implementation
		"""
		if close_fd is True:
			self.__server_socket.close()
		self.__server_socket = None