table:columns can only appear before table:row, so the previous change of displaying report title showed that we generated invalid odf when displaying something before a report section using form_list. "something" is also fields from the report form itself, so before that change, we were generating invaliding odf sometimes (this case is not tested at the time beeing). This change simply don't display form_list headers, and we have more similar rendering if report section uses form_list of form_view.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@41067 20353a03-c40f-0410-a6d1-a30d3c3de9de