[Compose] Update acme-mailcow

docker-compose.yml

@@ -318,7 +318,7 @@ services:
     acme-mailcow:
       depends_on:
         - nginx-mailcow
-      image: mailcow/acme:1.63
+      image: mailcow/acme:1.64
       dns:
         - ${IPV4_NETWORK:-172.22.1}.254
       environment: