erp5_crm: fix a ZSQLCatalog warning that flood logs when aknowledgements are used

bt5/erp5_crm/SkinTemplateItem/portal_skins/erp5_crm/AcknowledgementTool_getUserUnreadAcknowledgementList.xml

@@ -59,7 +59,7 @@ down as less a possible the user interface\n
 """\n
 from DateTime import DateTime\n
 \n
-user_name = context.portal_membership.getAuthenticatedMember()\n
+user_name = str(context.portal_membership.getAuthenticatedMember())\n
 \n
 def getUnreadAcknowledgementListForUser(user_name=None):\n
   # We give the portal type "Mass Notification" for now, we can\n

bt5/erp5_crm/bt/revision

-704
+705
\ No newline at end of file