LOCK-folder handling not correct

Describe the bug
Any local user can prevent schnapps from starting.

If schnapps is started without proper authorization a LOCK folder is created anyway.

However, this will not be deleted again.
This causes all following starts of schnapps to fail.

A reboot or manual deletion of the folder is necessary

To Reproduce
$ sudo -u nobody schnapps
'''
ERROR: not a valid btrfs filesystem: /
ERROR: unable to access : No such file or directory
mount: only root can use "--options" option
Can't mount root partition
'''

'# schnapps list
''' mkdir: can't create directory '/tmp/schnapps.lock': File exists
Another instance seems to be running!
'''

Expected behavior
schnapps cron-job starts despite the single start of another user

Environment
OS: Turris-OS 5
Snapshot version: 2.3-1 (also checked actually git version )