IP address on which RabbitMQ will listen for AMQP connections. Set to the empty string to listen on all interfaces. Note that RabbitMQ creates a user named guest with password guest by default, so you should delete this user if you intend to allow external access.
Together with 'port' setting it's mostly an alias for configItems."listeners.tcp.1" and it's left for backwards compatibility with previous version of this module.