make sure to always have a list of 3 items returned

bt5/erp5_payroll/SkinTemplateItem/portal_skins/erp5_payroll/PaySheetModelLine_asCellRange.xml

@@ -104,6 +104,8 @@ if matrixbox :\n
       cell_range.append(category_cell_range)\n
 \n
     cell_range = filter(lambda x: x != [], cell_range)\n
+  while len(cell_range) < 3:\n
+    cell_range.append([])\n
   return cell_range\n
 else:\n
   list_of_category_list = []\n

bt5/erp5_payroll/bt/revision

-585
\ No newline at end of file
+586
\ No newline at end of file