stack: Remove duplicated extends

stack/monitor/buildout.cfg

@@ -5,10 +5,7 @@ extends =
   ../../component/apache/buildout.cfg
   ../../component/curl/buildout.cfg
   ../../component/dash/buildout.cfg
-  ../../component/dcron/buildout.cfg
   ../../component/openssl/buildout.cfg
-  ../../component/logrotate/buildout.cfg
-  ../../component/gzip/buildout.cfg
   ../../component/lxml-python/buildout.cfg
   ../../component/pycurl/buildout.cfg
   ../../component/python-cryptography/buildout.cfg

stack/resilient/buildout.cfg

 [buildout]
 extends =
   buildout.hash.cfg
-  ../../component/apache/buildout.cfg
   ../../component/bash/buildout.cfg
   ../../component/dropbear/buildout.cfg
   ../../component/openssh/buildout.cfg
-  ../../component/gzip/buildout.cfg
   ../../component/rdiff-backup/buildout.cfg
   ../../component/rsync/buildout.cfg
   ../monitor/buildout.cfg