Files under /etc/maas are not removed when maas is uninstalled

[Jacopo Rota]

on maas 3.5 deb we are missing to delete some files under `/etc/maas` when we uninstall maas. If maas is reinstalled later, the same uid/gid of the old maas user might be assigned to another user (`avahi` for example)

ubuntu@leafeon:~$ ls -al /etc/maas
total 44
drwxr-xr-x 4 maas maas 4096 Apr 5 07:52 .
drwxr-xr-x 131 root root 12288 Apr 5 07:20 ..
-rw------- 1 avahi avahi 285 Apr 4 15:13 agent.yaml
drwxr-xr-x 2 maas maas 4096 Apr 2 21:18 certificates
-rw-r--r-- 1 root root 5204 Apr 2 21:18 drivers.yaml
drwxr-xr-x 2 root root 4096 Apr 5 07:13 preseeds
-rw-r----- 1 maas maas 40 Apr 5 07:16 rackd.conf
-rw-r----- 1 maas maas 156 Apr 5 07:15 regiond.conf

[Anton Troyanov (troyanov)]

We need to check how that will affect upgrades and maybe make a note if/what should be backed up before updating to a newer MAAS version

[Jacopo Rota (r00ta)]

As `agent.yaml` and `certificates` are generated by MAAS and are not supposed to be modified by the user I think it's fine to remove them.
MAAS should re-generate then in any case

[Alessandro Marcolini (alemar99)]

ack, will send the patch then