fix mem leak
fix mem leak

cloudjanak/NWPusher,cuocsongquanhta/NWPusher,noodlewerk/NWPusher,JinlianWang/NWPusher,AriX/NWPusher,JinlianWang/NWPusher,noodlewerk/NWPusher,cloudjanak/NWPusher,cuocsongquanhta/NWPusher,AriX/NWPusher