Fix syntax.

In current implementation, PlanningBox will generate conflict errors, as data
are saved on Widget object each time a PlanningBox is rendered. It has to be
fixed.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@14812 20353a03-c40f-0410-a6d1-a30d3c3de9de