new_line_to_br returns "None" for None

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@25819 20353a03-c40f-0410-a6d1-a30d3c3de9de

bt5/erp5_crm/SkinTemplateItem/portal_skins/erp5_crm/Event_getTextContentCorrespondToFormat.xml

@@ -64,7 +64,7 @@ else:\n
   if editable:\n
     return value\n
   else:\n
-    return newline_to_br(value)\n
+    return newline_to_br(value or "")\n
 </string> </value>
         </item>
         <item>

bt5/erp5_crm/bt/revision

-346
\ No newline at end of file
+348
\ No newline at end of file