Backup alert bug

[NoWiS-]

Describe the bug

Cron report a failure to execute the monitoring of a backup:

Mail subject:

Cron <root@SERVER> : Monitor BACKUP_NAME backup ; ALERT_DELAY="$(grep '^alert_delay: ' /etc/yunohost/apps/borgserver/settings.yml | awk '{print $2}')"; [[ $(find /home/BACKUP_NAME/backup/data -follow -mtime -${ALERT_DELAY} -ls | wc -l) > 0 ]] || ( echo "No file has been backuped in /home/BACKUP_NAME since ${ALERT_DELAY} days" | mail -s "[YNH] Backup missing : BACKUP_NAME" $(grep '^alert_mails: ' /etc/yunohost/apps/borgserver/settings.yml | awk '{print $2}'))

Mail content:

find: invalid argument `-'1'' to `-mtime'

Context

• YunoHost version: 4.3.2.2
• I have access to my server: Through SSH | through the webadmin | direct access via keyboard / screen | ...
• Are you in a special context or did you perform some particular tweaking on your YunoHost instance?: no
• Using package version: 1.1.16~ynh7