Update ros2-over-ethernet.rst to fix issue with ip adresses of companion and ardupilot

[nido009]

changed IP-Adresse of Ardupilot and Companion-Computer to match the config-parameters in the table below. stumbled upon this when trying to find out if the DDS_IP-Parameters shall have the IP of the Companion or the Ardupilot itself.

[rmackay9]

I'm probably misunderstanding but by default, AP autopilots should have the IP address of 192.168.144.14 I think. In general if we can stick with the defaults that should make it easier for users to setup the system

[Ryanf55]

Question - the defaults look to be set here in AP_Networking_config.h.

The values supplied in the wiki was just a hypothetical from the addresses my DHCP server gave them.

// Default Static IP Address: 192.168.144.14
#ifndef AP_NETWORKING_DEFAULT_STATIC_IP_ADDR
#define AP_NETWORKING_DEFAULT_STATIC_IP_ADDR "192.168.144.14"
#endif

Maybe we should say :

* An autopilot has the IP address ``192.168.144.14``
* A Computer running the MicroROS agent has the IP address ``192.168.144.6``
* The MicroROS agent is running on port ``2019``

This would match the rest of the ethernet wikis that have now been written.