update fpm listen chmod

src/templates/php-fpm.twig

@@ -4,7 +4,7 @@ group = {{ SYSTEM_USER_GROUP }}
 listen = 127.0.0.1:{{ PHP_FPM_PORT }}
 listen.owner = {{ SYSTEM_USER_USERNAME }}
 listen.group = {{ SYSTEM_USER_GROUP }}
-;listen.mode = 0660
+listen.mode = 0600
 listen.allowed_clients = 127.0.0.1
 pm = dynamic
 pm.max_children = 5