beesd: Method of identifying blkdev from UUID fails after initial device removed live

[nroach44]

1. Have BTRFS volume over two disks
2. Remove the first volume, and do not reboot
3. Attempt to configure and start beesd
4. Observe failure of service:

ERROR: Disk not contain btrfs: /dev/disk/by-uuid/051a6352-2b2a-4f96-ba4b-dbebd2eef8a2

ls -la /dev/disk/by-uuid/051a6352-2b2a-4f96-ba4b-dbebd2eef8a2
lrwxrwxrwx 1 root root 10 Apr 23 15:55 /dev/disk/by-uuid/051a6352-2b2a-4f96-ba4b-dbebd2eef8a2 -> ../../sda3

btrfs fi show
Label: none  uuid: 051a6352-2b2a-4f96-ba4b-dbebd2eef8a2
        Total devices 2 FS bytes used 1.60TiB
        devid    1 size 2.39TiB used 2.18TiB path /dev/mapper/a-b
        devid    3 size 3.54TiB used 144.03GiB path /dev/sdb3

I'm aware that rebooting should fix this.

As a side note, I found it quite weird that we specify the systemd unit with the UUID, not the file name. It feels strange that the tool has to investigate all of the /etc/beesd/*.conf files to find the UUID, instead of just using the file name (e.g. beesd@datalake.service -> /etc/beesd/datalake.conf) for the service template.