borg-client: Dump postgresql database to /root if it is running

roles/borg-client/templates/borg-backup.sh.j2

 #!/usr/bin/env bash
 
+# In case there is postgresql running, dump all of it somewhere.
+systemctl status postgresql && pg_dumpall -f /root/postgres_dump.sql
+
 borg create -v --stats -C lz4 -e /proc \
     -e /sys -e /dev -e /run -e /tmp -e /var/cache \
     {{ backup_host }}:{{ backup_dir }}::$(date -I) /