[NC] Add elastic labels for db

nextcloud/docker-compose.yml

@@ -38,6 +38,8 @@ services:
       - ${DATA_PATH}/my.cnf:/etc/mysql/my.cnf:ro
       - ${DATA_PATH}/db:/var/lib/mysql
     env_file: secrets/db.secrets
+    labels:
+      - "co.elastic.logs/module=mysql"
 
   app:
     image: nextcloud:21.0.5