fix: [rsync-backup-target] force restart when config changed

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

rsync-backup-target/hooks/init

@@ -47,9 +47,19 @@ while read-0 ident key; do
     keys["$key"]="$ident"
 done < <(echo "$keys" | shyaml key-values-0)
 
+debug "Adding config hash to enable recreating upon config change."
+config_hash=$({
+                 ## XXXvlab: ``env -i`` sole purpose is to protect find
+                 ## against big shell environments, and prevent it to fail.
+                 env -i find "${host_path_key}" \
+                      -name \*.pub -exec md5sum {} \;
+             } | md5_compat) || exit 1
+
 init-config-add "\
 $SERVICE_NAME:
   volumes:
     - $host_path_key:$local_path_key:ro
+  labels:
+    - compose.config_hash=$config_hash
 "