Added version check on FIND_PACKAGE(PkgConfig) to attempt to fix build with older versions of CMake
Added version check on FIND_PACKAGE(PkgConfig) to attempt to fix build with older versions of CMake


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