chg: doc: add ``-R`` to ``compose-add-rsync-key`` call in backup script

Signed-off-by: Valentin Lab <valentin.lab@kalysto.org>

README.org

@@ -726,6 +726,8 @@ backupper.
 
 #+begin_src sh
 DOMAIN=xxx.fr
+
+## CODE
 BACKUP_SERVER=core-06.0k.io:10023
 
 ssh-keygen -t rsa -N "" -f /root/.ssh/rsync_rsa -C "rsync@$DOMAIN"
@@ -743,10 +745,9 @@ dest="$BACKUP_SERVER"
 dest="${dest%/*}"
 dest="${dest%%:*}"
 echo "Contacting '$dest' host, to add key in authorized key:"
-ssh -o "StrictHostKeyChecking=no" "root@${dest}" -- compose-add-rsync-key "\"$DOMAIN\"" "\"$(cat /root/.ssh/rsync_rsa.pub)\""
+ssh -o "StrictHostKeyChecking=no" "root@${dest}" -- compose-add-rsync-key -R "\"$DOMAIN\"" "\"$(cat /root/.ssh/rsync_rsa.pub)\""
 
 
-compose build mongo ## force the build of the new mongo image with regular dumps
 #+end_src
 
 **** Installation du backup sur une installe mailcow