Fixed Coverity issue.
Fixed Coverity issue.

CID 11694: Uninitialized scalar field (UNINIT_CTOR)
Non-static class member _isARBOcclusionQuerySupported is not initialized in this constructor nor in any functions that it calls.



omega-hub/osg,stmh/osg,ghub/osg,omega-hub/osg,ghub/osg,koshman86/osg,koshman86/osg,koshman86/osg,XiaoCC/osg,artoolkit/osg,XiaoCC/osg,stmh/osg,omega-hub/osg,stmh/osg,ghub/osg,ghub/osg,XiaoCC/osg,artoolkit/osg,ntoand/osg,koshman86/osg,artoolkit/osg,ntoand/osg,omega-hub/osg,ntoand/osg,ntoand/osg,stmh/osg,artoolkit/osg,XiaoCC/osg,XiaoCC/osg,stmh/osg