make TestClearOldNotifications pass even when it runs really fast (executing on same timestamp)
diff --git a/Allura/allura/scripts/clear_old_notifications.py b/Allura/allura/scripts/clear_old_notifications.py
index 7ad3d49..61923e1 100644
--- a/Allura/allura/scripts/clear_old_notifications.py
+++ b/Allura/allura/scripts/clear_old_notifications.py
@@ -40,7 +40,7 @@
     def execute(cls, options):
         before = datetime.utcnow() - timedelta(days=options.back_days)
         M.Notification.query.remove({
-            'pubdate': {'$lt': before}
+            'pubdate': {'$lte': before}
         })