[PHP-FPM] Update libs, add gnupg

docker-compose.yml

@@ -100,7 +100,7 @@ services:
             - rspamd
 
     php-fpm-mailcow:
-      image: mailcow/phpfpm:1.56
+      image: mailcow/phpfpm:1.57
       command: "php-fpm -d date.timezone=${TZ} -d expose_php=0"
       depends_on:
         - redis-mailcow