Pick up zope 2.2.19

From original changelog:

- Fixed a serious privilege escalation issue. For more information see:
  http://plone.org/products/plone/security/advisories/20110622

stack/erp5.cfg

@@ -28,7 +28,7 @@ allow-hosts =
 
 extends =
 # Exact version of Zope
-  http://svn.zope.org/repos/main/Zope/tags/2.12.18/versions.cfg
+  http://svn.zope.org/repos/main/Zope/tags/2.12.19/versions.cfg
   ../component/logrotate/buildout.cfg
   ../component/dcron/buildout.cfg
   ../component/file/buildout.cfg