lamp: remove redundant items in buildout:parts

This fixes the nextcloud SR, which was broken by
commit 92779bf4
(mariadb is not a part anymore).

stack/lamp/buildout.cfg

@@ -4,20 +4,13 @@ ignore-existing = true
 
 parts =
   slapos-cookbook
-  apache-php
   php-redis
   php-imagick
   php-apcu
-  mariadb
-  mroonga-mariadb
   dropbear
   eggs
   instance
 
-  instance-apache-php
-  template-mariadb
-  instance-lamp
-
 extends =
   buildout.hash.cfg
   ../../component/curl/buildout.cfg