Fix cached_request argument in presence of cache_buster_fetcher
Fix cached_request argument in presence of cache_buster_fetcher

manueltimita/Windshaft,HydroLogic/Windshaft,manueltimita/Windshaft,CartoDB/Windshaft,wsw0108/Windshaft,HydroLogic/Windshaft,CartoDB/Windshaft,manueltimita/Windshaft,wsw0108/Windshaft,wsw0108/Windshaft,HydroLogic/Windshaft,CartoDB/Windshaft