stop raising 500 when uuid is not valid

tournaments/views.py

@@ -416,7 +416,7 @@ def event(request, event_id):
     )
 
 def tournament(request, tournament_id):
-
+    try:
         tournament = get_object_or_404(
             Tournament.objects.select_related('event')
             .prefetch_related(
@@ -438,6 +438,8 @@ def tournament(request, tournament_id):
             ),
             pk=tournament_id
         )
+    except ValidationError:
+        raise Http404("Tournament not found")
 
     round_id = request.GET.get('round')
     group_stage_id = request.GET.get('group_stage')