Fix max tracking bug in windowing example.
Fix max tracking bug in windowing example.

paulmartel/voltdb,creative-quant/voltdb,simonzhangsm/voltdb,flybird119/voltdb,ingted/voltdb,simonzhangsm/voltdb,migue/voltdb,VoltDB/voltdb,flybird119/voltdb,flybird119/voltdb,wolffcm/voltdb,VoltDB/voltdb,wolffcm/voltdb,VoltDB/voltdb,deerwalk/voltdb,wolffcm/voltdb,kumarrus/voltdb,zuowang/voltdb,zuowang/voltdb,deerwalk/voltdb,kumarrus/voltdb,ingted/voltdb,paulmartel/voltdb,paulmartel/voltdb,deerwalk/voltdb,zuowang/voltdb,ingted/voltdb,migue/voltdb,ingted/voltdb,simonzhangsm/voltdb,zuowang/voltdb,ingted/voltdb,VoltDB/voltdb,flybird119/voltdb,simonzhangsm/voltdb,VoltDB/voltdb,zuowang/voltdb,paulmartel/voltdb,ingted/voltdb,simonzhangsm/voltdb,migue/voltdb,kumarrus/voltdb,paulmartel/voltdb,deerwalk/voltdb,creative-quant/voltdb,migue/voltdb,VoltDB/voltdb,wolffcm/voltdb,kumarrus/voltdb,creative-quant/voltdb,flybird119/voltdb,wolffcm/voltdb,kumarrus/voltdb,paulmartel/voltdb,deerwalk/voltdb,zuowang/voltdb,wolffcm/voltdb,deerwalk/voltdb,kumarrus/voltdb,ingted/voltdb,zuowang/voltdb,kumarrus/voltdb,creative-quant/voltdb,creative-quant/voltdb,migue/voltdb,wolffcm/voltdb,creative-quant/voltdb,simonzhangsm/voltdb,flybird119/voltdb,deerwalk/voltdb,paulmartel/voltdb,ingted/voltdb,VoltDB/voltdb,creative-quant/voltdb,zuowang/voltdb,flybird119/voltdb,deerwalk/voltdb,wolffcm/voltdb,kumarrus/voltdb,simonzhangsm/voltdb,simonzhangsm/voltdb,flybird119/voltdb,creative-quant/voltdb,paulmartel/voltdb,migue/voltdb,migue/voltdb,migue/voltdb