QGC connection doubled when using topside as DHCP client

Since #3254:

This indeed makes QGC connection doubled:

1. First, clean all QGC stuff:

```bash
\rm -rf \
~/.cache/QGroundControl.org \
~/.cache/QGCMapCache300 \
~/Documents/QGroundControl \
~/.config/QGroundControl.org
```

2. Then, use the following setup:
- Vehicle with static IP (192.168.2.2) + DHCP Server (192.168.2.x)
- Topside computer as DHCP client (leased as 192.168.2.184)

3. Then, when opening QGC:
- QGC connects immediately
- QGC finds and shows the video stream + video controls
- QGC reports Heartbeat and other messages at doubled rate (heartbeat at 2Hz, etc)
- Text messages are all doubled:

4. If I remove one of the IPs, the messages are then at normal rate (not doubled)

_Originally posted by @joaoantoniocardoso in https://github.com/bluerobotics/BlueOS/pull/3509#pullrequestreview-3174151981_