Invalid Topic name with multi_topic=1

[aapatni]

[livox_ros_driver2_node-2] terminate called after throwing an instance of 'rclcpp::exceptions::InvalidTopicNameError'
[livox_ros_driver2_node-2]   what():  Invalid topic name: topic name token must not start with a number:
[livox_ros_driver2_node-2]   'livox/192_168_0_155/imu'

The naming convention of using the ip_address in the topic name is invalid as ROS2 does not allow for topics to start with a number