[Compose] Update Postfix and Watchdog images

docker-compose.yml

@@ -251,7 +251,7 @@ services:
             - dovecot
 
     postfix-mailcow:
-      image: mailcow/postfix:1.55
+      image: mailcow/postfix:1.56
       depends_on:
         - mysql-mailcow
       volumes:
@@ -401,7 +401,7 @@ services:
         - /lib/modules:/lib/modules:ro
 
     watchdog-mailcow:
-      image: mailcow/watchdog:1.83
+      image: mailcow/watchdog:1.84
       # Debug
       #command: /watchdog.sh
       dns: