Protect against undefined updater
Protect against undefined updater

YonatanKra/cesium,progsung/cesium,geoscan/cesium,kaktus40/cesium,YonatanKra/cesium,kaktus40/cesium,progsung/cesium,AnalyticalGraphicsInc/cesium,jasonbeverage/cesium,CesiumGS/cesium,josh-bernstein/cesium,CesiumGS/cesium,likangning93/cesium,CesiumGS/cesium,likangning93/cesium,CesiumGS/cesium,CesiumGS/cesium,josh-bernstein/cesium,jasonbeverage/cesium,YonatanKra/cesium,likangning93/cesium,likangning93/cesium,AnalyticalGraphicsInc/cesium,YonatanKra/cesium,geoscan/cesium,likangning93/cesium