Alarm: do not sort by id cast as UNSIGNED

It can only work with default id generator and anyway catalog does not
understand this syntax, so this has no effect

product/ERP5/Document/Alarm.py

@@ -347,9 +347,7 @@ Alarm Tool Node: %s
       limit = self.isActive() and 2 or 1
     active_process_list = self.getPortalObject().portal_catalog(
       portal_type='Active Process', limit=limit,
-      sort_on=(('creation_date', 'DESC'),
-               # XXX Work around poor resolution of MySQL dates.
-               ('CONVERT(`catalog`.`id`, UNSIGNED)', 'DESC')),
+      sort_on=(('creation_date', 'DESC'),),
       causality_uid=self.getUid())
     if len(active_process_list) < limit:
       process = None