Update ghost/docker-compose.yml

Ensure that mysql database remains on the same node; if it goes down add the label to another node and hope that the databases have been replicated properly

ghost/docker-compose.yml

@@ -38,9 +38,9 @@ services:
     image: mysql:8.4.6      # latest or last version of version 8; Ghost doesn't recognise version 9
     container_name: mysql
     deploy:
-#      placement:
-#        constraints: [node.role == worker]
-      replicas: 1
+      placement:
+        constraints:
+          - node.labels.database == here
     restart: always
     volumes:
       - /mnt/cephfs/docker/ghost/mysql:/var/lib/mysql:rw