remove WaitToRead in dist-kvstore (#7489)
remove WaitToRead in dist-kvstore (#7489)

* remove waittoread in dist-kv

* update

zhreshold/mxnet,larroy/mxnet,LinkHS/incubator-mxnet,solin319/incubator-mxnet,nicklhy/mxnet,reminisce/mxnet,thirdwing/mxnet,ykim362/mxnet,formath/mxnet,ptrendx/mxnet,DickJC123/mxnet,zhreshold/mxnet,crazy-cat/incubator-mxnet,eric-haibin-lin/mxnet,ykim362/mxnet,larroy/mxnet,xcgoner/dist-mxnet,ShownX/incubator-mxnet,sergeykolychev/mxnet,eric-haibin-lin/mxnet,nicklhy/mxnet,saurabh3949/mxnet,LinkHS/incubator-mxnet,kkk669/mxnet,madjam/mxnet,madjam/mxnet,hpi-xnor/BMXNet,mbaijal/incubator-mxnet,CodingCat/mxnet,ShownX/incubator-mxnet,CodingCat/mxnet,reminisce/mxnet,weleen/mxnet,navrasio/mxnet,saurabh3949/mxnet,eric-haibin-lin/mxnet,crazy-cat/incubator-mxnet,precedenceguo/mxnet,Northrend/mxnet,xcgoner/dist-mxnet,formath/mxnet,jermainewang/mxnet,tornadomeet/mxnet,gautamkmr/incubator-mxnet,weleen/mxnet,ykim362/mxnet,gautamkmr/incubator-mxnet,sxjscience/mxnet,fullfanta/mxnet,stefanhenneking/mxnet,vikingMei/mxnet,thirdwing/mxnet,eric-haibin-lin/mxnet,dmlc/mxnet,thirdwing/mxnet,ShownX/incubator-mxnet,sergeykolychev/mxnet,TuSimple/mxnet,formath/mxnet,antoan2/incubator-mxnet,navrasio/mxnet,sxjscience/mxnet,jennyzhang0215/incubator-mxnet,sxjscience/mxnet,madjam/mxnet,TuSimple/mxnet,Northrend/mxnet,leezu/mxnet,jennyzhang0215/incubator-mxnet,gautamkmr/incubator-mxnet,tlby/mxnet,jamesliu/mxnet,tlby/mxnet,DickJC123/mxnet,antoan2/incubator-mxnet,TuSimple/mxnet,nicklhy/mxnet,eric-haibin-lin/mxnet,jennyzhang0215/incubator-mxnet,solin319/incubator-mxnet,thirdwing/mxnet,jennyzhang0215/incubator-mxnet,stefanhenneking/mxnet,kkk669/mxnet,ykim362/mxnet,vikingMei/mxnet,antoan2/incubator-mxnet,madjam/mxnet,apache/incubator-mxnet,zhreshold/mxnet,weleen/mxnet,rahul003/mxnet,TuSimple/mxnet,yuruofeifei/mxnet,reminisce/mxnet,ptrendx/mxnet,larroy/mxnet,rahul003/mxnet,jiajiechen/mxnet,solin319/incubator-mxnet,larroy/mxnet,TuSimple/mxnet,yuruofeifei/mxnet,szha/mxnet,ptrendx/mxnet,ZihengJiang/mxnet,solin319/incubator-mxnet,stefanhenneking/mxnet,jamesliu/mxnet,smolix/incubator-mxnet,mbaijal/incubator-mxnet,stefanhenneking/mxnet,ZihengJiang/mxnet,antoan2/incubator-mxnet,sergeykolychev/mxnet,navrasio/mxnet,ZihengJiang/mxnet,sergeykolychev/mxnet,yuruofeifei/mxnet,ZihengJiang/mxnet,larroy/mxnet,wangyum/mxnet,tlby/mxnet,crazy-cat/incubator-mxnet,yuruofeifei/mxnet,yajiedesign/mxnet,vikingMei/mxnet,yuruofeifei/mxnet,kevinthesun/mxnet,szha/mxnet,thirdwing/mxnet,jermainewang/mxnet,LinkHS/incubator-mxnet,thirdwing/mxnet,TuSimple/mxnet,jiajiechen/mxnet,jennyzhang0215/incubator-mxnet,formath/mxnet,sergeykolychev/mxnet,crazy-cat/incubator-mxnet,formath/mxnet,fullfanta/mxnet,nicklhy/mxnet,madjam/mxnet,rahul003/mxnet,crazy-cat/incubator-mxnet,tlby/mxnet,stefanhenneking/mxnet,rahul003/mxnet,ptrendx/mxnet,vikingMei/mxnet,CodingCat/mxnet,precedenceguo/mxnet,luoyetx/mxnet,kkk669/mxnet,Prasad9/incubator-mxnet,sergeykolychev/mxnet,LinkHS/incubator-mxnet,luoyetx/mxnet,larroy/mxnet,tornadomeet/mxnet,ShownX/incubator-mxnet,reminisce/mxnet,smolix/incubator-mxnet,indhub/mxnet,tornadomeet/mxnet,hpi-xnor/BMXNet,ForkedReposBak/mxnet,Prasad9/incubator-mxnet,mbaijal/incubator-mxnet,wangyum/mxnet,crazy-cat/incubator-mxnet,weleen/mxnet,sergeykolychev/mxnet,dmlc/mxnet,wangyum/mxnet,reminisce/mxnet,navrasio/mxnet,reminisce/mxnet,luoyetx/mxnet,Mega-DatA-Lab/mxnet,madjam/mxnet,wangyum/mxnet,kkk669/mxnet,Northrend/mxnet,dmlc/mxnet,yuruofeifei/mxnet,solin319/incubator-mxnet,yajiedesign/mxnet,LinkHS/incubator-mxnet,zhreshold/mxnet,indhub/mxnet,yajiedesign/mxnet,piiswrong/mxnet,reminisce/mxnet,formath/mxnet,tornadomeet/mxnet,thirdwing/mxnet,eric-haibin-lin/mxnet,weleen/mxnet,Mega-DatA-Lab/mxnet,jamesliu/mxnet,ptrendx/mxnet,sergeykolychev/mxnet,Mega-DatA-Lab/mxnet,nicklhy/mxnet,vikingMei/mxnet,gautamkmr/incubator-mxnet,navrasio/mxnet,hpi-xnor/BMXNet,navrasio/mxnet,jiajiechen/mxnet,eric-haibin-lin/mxnet,CodingCat/mxnet,ShownX/incubator-mxnet,stefanhenneking/mxnet,wangyum/mxnet,smolix/incubator-mxnet,dmlc/mxnet,xcgoner/dist-mxnet,CodingCat/mxnet,luoyetx/mxnet,LinkHS/incubator-mxnet,hpi-xnor/BMXNet,smolix/incubator-mxnet,tlby/mxnet,mbaijal/incubator-mxnet,zhreshold/mxnet,Northrend/mxnet,dmlc/mxnet,mbaijal/incubator-mxnet,kkk669/mxnet,fullfanta/mxnet,precedenceguo/mxnet,jamesliu/mxnet,dmlc/mxnet,luoyetx/mxnet,jennyzhang0215/incubator-mxnet,indhub/mxnet,szha/mxnet,CodingCat/mxnet,jamesliu/mxnet,crazy-cat/incubator-mxnet,sxjscience/mxnet,weleen/mxnet,xcgoner/dist-mxnet,xcgoner/dist-mxnet,jermainewang/mxnet,jiajiechen/mxnet,saurabh3949/mxnet,weleen/mxnet,leezu/mxnet,reminisce/mxnet,ForkedReposBak/mxnet,saurabh3949/mxnet,Prasad9/incubator-mxnet,rahul003/mxnet,fullfanta/mxnet,vikingMei/mxnet,Northrend/mxnet,ShownX/incubator-mxnet,kevinthesun/mxnet,ForkedReposBak/mxnet,vikingMei/mxnet,jennyzhang0215/incubator-mxnet,sxjscience/mxnet,TuSimple/mxnet,rahul003/mxnet,zhreshold/mxnet,dmlc/mxnet,weleen/mxnet,Prasad9/incubator-mxnet,kevinthesun/mxnet,vikingMei/mxnet,stefanhenneking/mxnet,luoyetx/mxnet,yuruofeifei/mxnet,ForkedReposBak/mxnet,madjam/mxnet,dmlc/mxnet,ZihengJiang/mxnet,Northrend/mxnet,TuSimple/mxnet,kevinthesun/mxnet,jiajiechen/mxnet,madjam/mxnet,ZihengJiang/mxnet,piiswrong/mxnet,antoan2/incubator-mxnet,gautamkmr/incubator-mxnet,jermainewang/mxnet,leezu/mxnet,smolix/incubator-mxnet,precedenceguo/mxnet,ptrendx/mxnet,reminisce/mxnet,yuruofeifei/mxnet,navrasio/mxnet,antoan2/incubator-mxnet,yajiedesign/mxnet,ZihengJiang/mxnet,Mega-DatA-Lab/mxnet,hpi-xnor/BMXNet,ykim362/mxnet,kkk669/mxnet,ykim362/mxnet,yajiedesign/mxnet,leezu/mxnet,tlby/mxnet,indhub/mxnet,jiajiechen/mxnet,eric-haibin-lin/mxnet,ShownX/incubator-mxnet,thirdwing/mxnet,jamesliu/mxnet,smolix/incubator-mxnet,DickJC123/mxnet,yuruofeifei/mxnet,xcgoner/dist-mxnet,apache/incubator-mxnet,mbaijal/incubator-mxnet,wangyum/mxnet,ForkedReposBak/mxnet,leezu/mxnet,solin319/incubator-mxnet,gautamkmr/incubator-mxnet,wangyum/mxnet,dmlc/mxnet,jermainewang/mxnet,sxjscience/mxnet,Prasad9/incubator-mxnet,precedenceguo/mxnet,saurabh3949/mxnet,Prasad9/incubator-mxnet,larroy/mxnet,piiswrong/mxnet,DickJC123/mxnet,szha/mxnet,xcgoner/dist-mxnet,CodingCat/mxnet,ForkedReposBak/mxnet,solin319/incubator-mxnet,weleen/mxnet,rahul003/mxnet,sxjscience/mxnet,madjam/mxnet,rahul003/mxnet,Prasad9/incubator-mxnet,xcgoner/dist-mxnet,LinkHS/incubator-mxnet,gautamkmr/incubator-mxnet,yajiedesign/mxnet,tlby/mxnet,zhreshold/mxnet,Prasad9/incubator-mxnet,kevinthesun/mxnet,yajiedesign/mxnet,crazy-cat/incubator-mxnet,jermainewang/mxnet,ptrendx/mxnet,CodingCat/mxnet,jennyzhang0215/incubator-mxnet,zhreshold/mxnet,jermainewang/mxnet,saurabh3949/mxnet,yajiedesign/mxnet,hpi-xnor/BMXNet,piiswrong/mxnet,indhub/mxnet,tornadomeet/mxnet,leezu/mxnet,Northrend/mxnet,ykim362/mxnet,jennyzhang0215/incubator-mxnet,formath/mxnet,saurabh3949/mxnet,hpi-xnor/BMXNet,LinkHS/incubator-mxnet,apache/incubator-mxnet,jamesliu/mxnet,apache/incubator-mxnet,tornadomeet/mxnet,piiswrong/mxnet,jamesliu/mxnet,tornadomeet/mxnet,fullfanta/mxnet,ForkedReposBak/mxnet,navrasio/mxnet,solin319/incubator-mxnet,luoyetx/mxnet,gautamkmr/incubator-mxnet,stefanhenneking/mxnet,precedenceguo/mxnet,ptrendx/mxnet,Mega-DatA-Lab/mxnet,ShownX/incubator-mxnet,kkk669/mxnet,hpi-xnor/BMXNet,leezu/mxnet,thirdwing/mxnet,piiswrong/mxnet,tornadomeet/mxnet,larroy/mxnet,kkk669/mxnet,kkk669/mxnet,tlby/mxnet,kevinthesun/mxnet,leezu/mxnet,tlby/mxnet,larroy/mxnet,piiswrong/mxnet,piiswrong/mxnet,Mega-DatA-Lab/mxnet,ptrendx/mxnet,ForkedReposBak/mxnet,szha/mxnet,mbaijal/incubator-mxnet,LinkHS/incubator-mxnet,navrasio/mxnet,TuSimple/mxnet,antoan2/incubator-mxnet,hpi-xnor/BMXNet,jermainewang/mxnet,smolix/incubator-mxnet,ZihengJiang/mxnet,szha/mxnet,jiajiechen/mxnet,sergeykolychev/mxnet,saurabh3949/mxnet,ZihengJiang/mxnet,ykim362/mxnet,indhub/mxnet,luoyetx/mxnet,sxjscience/mxnet,indhub/mxnet,tlby/mxnet,kevinthesun/mxnet,szha/mxnet,fullfanta/mxnet,szha/mxnet,sxjscience/mxnet,ykim362/mxnet,leezu/mxnet,formath/mxnet,gautamkmr/incubator-mxnet,antoan2/incubator-mxnet,smolix/incubator-mxnet,CodingCat/mxnet,rahul003/mxnet,precedenceguo/mxnet,fullfanta/mxnet,nicklhy/mxnet,smolix/incubator-mxnet,Mega-DatA-Lab/mxnet,saurabh3949/mxnet,wangyum/mxnet,nicklhy/mxnet,fullfanta/mxnet,jiajiechen/mxnet,antoan2/incubator-mxnet,zhreshold/mxnet,Prasad9/incubator-mxnet,luoyetx/mxnet,nicklhy/mxnet,fullfanta/mxnet,solin319/incubator-mxnet,mbaijal/incubator-mxnet,formath/mxnet,jamesliu/mxnet,stefanhenneking/mxnet,ptrendx/mxnet,mbaijal/incubator-mxnet,szha/mxnet,ShownX/incubator-mxnet,reminisce/mxnet,TuSimple/mxnet,kevinthesun/mxnet,jermainewang/mxnet,indhub/mxnet,jiajiechen/mxnet,kevinthesun/mxnet,Mega-DatA-Lab/mxnet,wangyum/mxnet,tornadomeet/mxnet,Northrend/mxnet,crazy-cat/incubator-mxnet,precedenceguo/mxnet,nicklhy/mxnet,Northrend/mxnet,piiswrong/mxnet,yajiedesign/mxnet,Mega-DatA-Lab/mxnet,eric-haibin-lin/mxnet,xcgoner/dist-mxnet,vikingMei/mxnet,ForkedReposBak/mxnet,precedenceguo/mxnet,indhub/mxnet