fix pagination bug when page number less than 3
fix pagination bug when page number less than 3

xiaochen2012/CBoard,bigdata-eqxiu/CBoard,bigdata-eqxiu/CBoard,junjiem/CBoard,junjiem/CBoard,junjiem/CBoard,hjtoday/CBoard,hjtoday/CBoard,xiaochen2012/CBoard,yzhang921/CBoard,hjtoday/CBoard,xiaochen2012/CBoard,xiaochen2012/CBoard,yzhang921/CBoard,hjtoday/CBoard,yzhang921/CBoard,bigdata-eqxiu/CBoard,junjiem/CBoard,bigdata-eqxiu/CBoard,yzhang921/CBoard