fix empty prefix case for namescope (#7794)
fix empty prefix case for namescope (#7794)


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