Restoring Members filter backend for users endpoint

taiga/users/api.py

@@ -65,6 +65,7 @@ class UsersViewSet(ModelCrudViewSet):
     permission_classes = (permissions.UserPermission,)
     serializer_class = serializers.UserSerializer
     queryset = models.User.objects.all()
+    filter_backends = (MembersFilterBackend,)
 
     def pre_conditions_on_save(self, obj):
         if self.request.user.is_superuser: