Called when the process has stopped.

        :param returncode: Process returncode

def _termination_callback(self, process_name, returncode):
        """
        Called when the process has stopped.

        :param returncode: Process returncode
        """

        self._terminate_process_iou()
        if returncode != 0:
            if returncode == -11:
                message = 'IOU VM "{}" process has stopped with return code: {} (segfault). This could be an issue with the IOU image, using a different image may fix this.\n{}'.format(self.name,
                                                                                                                                                                                         returncode,
                                                                                                                                                                                         self.read_iou_stdout())
            else:
                message = 'IOU VM "{}" process has stopped with return code: {}\n{}'.format(self.name, returncode, self.read_iou_stdout())
            log.warning(message)
            self.project.emit("log.error", {"message": message})
        if self._telnet_server:
            self._telnet_server.close()
            self._telnet_server = None