queryTile: only use ETag, Last-Modified properties from upstream headers.
queryTile: only use ETag, Last-Modified properties from upstream headers.

kartotherian/kartotherian,nyurik/kartotherian,mapbox/tilelive-vector,nyurik/tilelive-vector,jaredbrookswhite/tilelive-vector,nyurik/kartotherian,kartotherian/kartotherian,kartotherian/kartotherian,kartotherian/kartotherian,nyurik/kartotherian,nyurik/kartotherian