Only validate new messages; All other states are subsequent to a validation (regular of by user's choice by modifying sql tables).
This fixes impossibility to invoke by hand validated messages not being executed when they have a serialization_tage set.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@22647 20353a03-c40f-0410-a6d1-a30d3c3de9de