item of text_list must be string.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@19013 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/AccountingTransaction.py

@@ -111,7 +111,7 @@ class AccountingTransaction(Delivery):
                     self.getStartDate(),
                     self.getStopDate(), ):
         if prop:
-          text_list.append(prop)
+          text_list.append(str(prop))
       return ' '.join(text_list)
 
 # Compatibility