fix prometheus metrics

common/borgbackup/templates/borgbackup-prometheus.sh

@@ -3,6 +3,9 @@
 export BORG_PASSPHRASE="{{repo_passphrase}}"
 export BORG_RSH="ssh -i /srv/borgbackup/repo_sshkey"
 
+# Force locale for correct formatting
+LANG=en_US.UTF-8
+
 # Metrics output file in the prometheus node-exporter directory 
 PROM_FILE="/var/lib/prometheus/node-exporter/borgbackup.prom"