From Stephan Huber, fix for crash on exit
From Stephan Huber, fix for crash on exit


marchelbling/osg,marchelbling/osg,tomasthoresen/osg,scrawl/osg,scrawl/osg,jtorresfabra/osg,jtorresfabra/osg,artoolkit/osg,artoolkit/osg,tomasthoresen/osg,marchelbling/osg,openscenegraph/osg,jtorresfabra/osg,tomasthoresen/osg,artoolkit/osg,openscenegraph/osg,jtorresfabra/osg,openscenegraph/osg,marchelbling/osg,scrawl/osg,scrawl/osg,artoolkit/osg,tomasthoresen/osg,openscenegraph/osg