Pre-fork we need to create the zmq router device

        :param func process_manager: An instance of salt.utils.process.ProcessManager

def pre_fork(self, process_manager):
        '''
        Pre-fork we need to create the zmq router device

        :param func process_manager: An instance of salt.utils.process.ProcessManager
        '''
        salt.transport.mixins.auth.AESReqServerMixin.pre_fork(self, process_manager)
        process_manager.add_process(self.zmq_device)