[Bug]: DayZ SA server config is not stored in backup

### User story

I made a backup of my server instance and copied it to a new server after restore the file /home/dayzserver/serverfiles/cfg/dayzserver.server.cfg was missing and on start the default config was copied. I couldn't find in the docs where to configure the config file to have it restored correctly.

### Game

DayZ SA

### Linux distro

RedHat 9

### Command

command: backup

### Further information

I have installed the dayzserver with dayzserver install, then configured mods and stuff and started it. After starting I changed the server Name, the Adminpassword and the number of slots and the motd. All in /home/dayzserver/serverfiles/cfg/dayzserver.server.cfg

Then after a while I made a backup of the server and copied it to a new host to test restore. And when I started it started with the default settings. Random admin password, hostname as LinuxGSM etc.

I check the documentation and for the love of my I can't find the correct way to make this config persistent on backup, so either the docs needs updates or on a backup /home/dayzserver/serverfiles/cfg/dayzserver.server.cfg has to be included.

### Relevant log output

_No response_

### Steps to reproduce

_No response_

Inizia con l’implementazione del comando di backup e con la sua gestione di /home/dayzserver/serverfiles/cfg/dayzserver.server.cfg; l’issue identifica il file mancante e lo scenario di ripristino di DayZ SA. Controlla la documentazione correlata alla configurazione dei backup, quindi riproduci un backup e un ripristino per confermare se la configurazione del server viene preservata e documenta o correggi il comportamento previsto.

Scritto dal modello di indicizzazione a partire dal testo della issue.