bug#46683: cuirass: reconfigure creates 'dbname=cuirass host=' folder

[Jonathan Brielmaier]

If I reconfigure a system with a simple-cuirass-service it creates a
'dbname=cuirass host=' named folder in the folder, where you run `guix
system reconfigure`.

$ sudo -E guix system reconfigure config.scm
[...]
$ $ ls

'dbname=cuirass host='/
[...]