erp5testnode: fix duplicated path error

The error was :

 Error: The following paths are already installed by other sections:
 {'/opt/slapgrid/4eb4146f38fc86ed2ad060217a1a95a6/bin/slapos-watchdog':
 'extra-eggs',
 '/opt/slapgrid/4eb4146f38fc86ed2ad060217a1a95a6/bin/networkcache-download':
 'slapos-cookbook',
 '/opt/slapgrid/4eb4146f38fc86ed2ad060217a1a95a6/bin/slapos':
 'extra-eggs',
 '/opt/slapgrid/4eb4146f38fc86ed2ad060217a1a95a6/bin/generate-signature-key':
 'slapos-cookbook',
 '/opt/slapgrid/4eb4146f38fc86ed2ad060217a1a95a6/bin/networkcache-upload':
 'slapos-cookbook'}

software/erp5testnode/software.cfg

@@ -27,8 +27,6 @@ recipe = zc.recipe.egg
 eggs =
   ${lxml-python:egg}
   zc.buildout
-  slapos.libnetworkcache
-  slapos.core
   slapos.recipe.template
   supervisor
   jsonschema