Added check to avoid doing update when the imagesequence is empty.
Added check to avoid doing update when the imagesequence is empty.


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