Comment 0 for bug 1944204

In the spirit of bug 1038422 I think we also need to exclude virtual interfaces.
At least in the usage for the motd headers.

In a common server you often find LXD, Libvirt and maybe some further bridges. So today when logging in I saw:

```
$ ssh -XY horsea
Welcome to Ubuntu 20.04.3 LTS (GNU/Linux 5.4.0-84-generic x86_64)

 * Documentation: https://help.ubuntu.com
 * Management: https://landscape.canonical.com
 * Support: https://ubuntu.com/advantage

  System information as of Mon Sep 20 14:17:06 UTC 2021

  System load: 1.19
  Usage of /: 18.5% of 228.17GB
  Memory usage: 75%
  Swap usage: 1%
  Temperature: 36.0 C
  Processes: 764
  Users logged in: 1
  IPv4 address for eno1: 10.245.168.39
  IPv4 address for eno50: 10.245.170.222
  IPv4 address for localbridge0: 10.0.21.1
  IPv4 address for localbridge2: 10.0.22.1
  IPv4 address for lxdbr0: 10.128.57.1
  IPv6 address for lxdbr0: fd42:97e3:9a49:c9a1::1
  IPv4 address for virbr0: 192.168.122.1

 * Super-optimized for small spaces - read how we shrank the memory
   footprint of MicroK8s to make it the smallest full K8s around.

   https://ubuntu.com/blog/microk8s-memory-optimisation

13 updates can be applied immediately.
To see these additional updates run: apt list --upgradable
```

IMHO this whole section:
```
  IPv4 address for localbridge0: 10.0.21.1
  IPv4 address for localbridge2: 10.0.22.1
  IPv4 address for lxdbr0: 10.128.57.1
  IPv6 address for lxdbr0: fd42:97e3:9a49:c9a1::1
  IPv4 address for virbr0: 192.168.122.1
```
isn't very useful.

I'd ask to (up to you) either remove it from landscape-sysinfo in general OR if you think that is more useful maybe call it only with --exclude-sysinfo-plugins=Network when using it for MOTD.