Update CHANGELOG.md

Author: gkjohnson

CHANGELOG.md

@@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## [0.4.24] - Unreleased
 ### Changed
 - EnvironmentControls: PivotMesh is now added to the scene before the "start" event is fired.
+- ImageOverlayPlugin: Do not allocate a render target for compositing if only a single tile is returned that exactly matches the tile bounds.
 
 ### Fixed
 - Ellipsoid.getPositionToCartographic: fixed incorrect calculation of cartographic point.