Fix layer not found when using raster map
Summary:
Fix T1377
Buffer trip request to avoid filling cache
Test Plan: Try the map, changing Settings → Style of the map under all combinations. No crashes.
Reviewers: valerio.bozzolan
Reviewed By: valerio.bozzolan
Subscribers: valerio.bozzolan, Libre BusTO
Tags: Libre BusTO
Maniphest Tasks: T1377
Differential Revision: https://gitpull.it/D216