removing a disk

# Issue report

## What version of MicroCeph are you using ?

ceph-version: 18.2.4-0ubuntu1~cloud0; microceph-git: c9f2b08f92
ubuntu running on raspberry pi cluster (2x4, 1x5)

Use this section to describe the channel/revision which produces the unexpected behaviour.
This information can be fetched from the `installed:` section of `sudo snap info microceph` output.

from snap: installed: 18.2.4+snapc9f2b08f92 (1140) 93MB held
## What are the steps to reproduce this issue ?

1. trying to remove an osd

## What happens (observed behaviour) ?
```bash
root@pi4:/etc/systemd/system# systemctl restart snap.microceph.osd.service
root@pi4:/etc/systemd/system# microceph disk remove osd.4
```
## What were you expecting to happen ?
remove osd.4

## Relevant logs, error output, etc.
```bash
Removing osd.4, timeout 1800s
Error: failed to get disks: failed listing disks: Get "http://control.socket/1.0/disks": dial unix /var/snap/microceph/common/state/control.socket: connect: no such file or directory
root@pi4:/etc/systemd/system# ceph osd tree
ID CLASS WEIGHT TYPE NAME STATUS REWEIGHT PRI-AFF
-1 0.45177 root default
-3 0.11189 host pi4
2 hdd 0 osd.2 up 1.00000 1.00000
4 hdd 0.11189 osd.4 up 1.00000 1.00000
-4 0.11249 host pi44
6 0.11249 osd.6 up 1.00000 1.00000
-2 0.22739 host pi5
1 hdd 0.22739 osd.1 up 1.00000 1.00000
```

If it’s considerably long, please paste to https://gist.github.com/ and insert the link here.

## Additional comments.

I'm running with USB drives 3x128, 1x256
I wanted to just use 128Gb and take the 256Gb out and add 1 on each host