Fix Spelling Error
Fix Spelling Error

_removeDefaultDataSoureListener - > _removeDefaultDataSourceListener
YonatanKra/cesium,likangning93/cesium,AnalyticalGraphicsInc/cesium,YonatanKra/cesium,CesiumGS/cesium,YonatanKra/cesium,jasonbeverage/cesium,progsung/cesium,YonatanKra/cesium,CesiumGS/cesium,jasonbeverage/cesium,CesiumGS/cesium,likangning93/cesium,likangning93/cesium,progsung/cesium,likangning93/cesium,likangning93/cesium,CesiumGS/cesium,AnalyticalGraphicsInc/cesium,CesiumGS/cesium