Fix crash on /bda/revente/<id>/manage

`annotate_paid` method is a method of the Participant object manager,
not the Participant class itself

bda/views.py

@@ -381,7 +381,7 @@ def revente_manage(request, tirage_id):
     - Annulation d'une revente après que le tirage a eu lieu
     """
     tirage = get_object_or_404(Tirage, id=tirage_id)
-    participant, created = Participant.annotate_paid().get_or_create(
+    participant, created = Participant.objects.annotate_paid().get_or_create(
         user=request.user, tirage=tirage
     )