fix issue with altitude if there is no elevation data
fix issue with altitude if there is no elevation data

robhawkes/WebViewer,robhawkes/WebViewer,OpenWebGlobe/WebViewer,OpenWebGlobe/WebViewer,Hvitnov/WebViewer,Hvitnov/WebViewer,robhawkes/WebViewer,robhawkes/WebViewer,OpenWebGlobe/WebViewer,Hvitnov/WebViewer,OpenWebGlobe/WebViewer,Hvitnov/WebViewer