erp5_accounting: return title as str in getProjectItemList

bt5/erp5_accounting/SkinTemplateItem/portal_skins/erp5_accounting/AccountingTransactionLine_getProjectItemList.py

@@ -21,7 +21,7 @@ if context.getPortalType() == 'Accounting Transaction Module':
 
   if not project_list:
     return [] # returning an empty list, not to add project column on reports
-  return [('', ''), (translateString('No Project'), 'None')] + project_list
+  return [('', ''), (str(translateString('No Project')), 'None')] + project_list
   
 # case 2: script is used on custom listfields.
 #  for now the script has to be customized in such case.