don't print uid of backup user

server/backup.sh

@@ -33,7 +33,7 @@ cd $BACKUP_DIR/tmp
 tar -zcf $BACKUP_FILE *
 
 #change owner of backup file only if user exists
-id -u $BACKUP_USER
+id -u $BACKUP_USER >/dev/null
 status=$?
 [ $status -eq 0 ] && chown $BACKUP_USER $BACKUP_FILE