nicer indented json encoding now also in rest api

src/c3nav/api/views/mapdata.py

@@ -4,6 +4,7 @@ import os
 from django.conf import settings
 from django.core.files import File
 from django.http import HttpResponse
+
 from rest_framework.decorators import detail_route
 from rest_framework.viewsets import ReadOnlyModelViewSet