storage: fix TestKeyIndexCompact
storage: fix TestKeyIndexCompact

It fails to pass before.

ktateish/etcd,etcd-io/etcd,chenbaihu/etcd,whuwxl/etcd,tguangch/etcd,purpleidea/etcd,Winslett/etcd,coreos/etcd,lumjjb/etcd,raoofm/etcd,betawaffle/etcd,Yhgenomics/etcd,yichengq/etcd,StorReduce/etcd,etcd-io/etcd,lumjjb/etcd,heyitsanthony/etcd,handsomesun/etcd,ajityagaty/etcd,jeremyeder/etcd,honeyqa/etcd,jonboulle/etcd,njucslqq/etcd,fasaxc/etcd,ajityagaty/etcd,cockroachdb/etcd,achanda/etcd,mkumatag/etcd,svdata/etcd,combk8s/etcd,siddontang/etcd,njucslqq/etcd,tguangch/etcd,qqsun8819/etcd,rnaveiras/etcd,plasticbox/etcd,kkaneda/etcd,cognusion/etcd,cchamplin/etcd,raoofm/etcd,HideoYamauchi/etcd,gae123/etcd,plasticbox/etcd,visheshnp/etcd,shakefu/etcd,bdarnell/etcd,rchicoli/etcd,tamird/etcd,fanminshi/etcd,mqliang/etcd,giantswarm/etcd,ajityagaty/etcd,svdata/etcd,visheshnp/etcd,imzhulei/etcd,gouyang/etcd,Yhgenomics/etcd,oscarrr110/etcd,glevand/coreos--etcd,luxas/etcd,mickep76/etcd,hroyrh/etcd,OyTao/etcd_learning,sayden/etcd,pauldallen/etcd,wantonsolutions/dinv-etcd,glevand/coreos--etcd,yudai/etcd,iamqizhao/etcd,nekto0n/etcd,CrazyJvm/etcd,wantonsolutions/dinv-etcd,chipironcin/etcd,OyTao/etcd_learning,Eagle-X/etcd,rnaveiras/etcd,fgbreel/etcd,cockroachdb/etcd,mickep76/etcd,dnaeon/etcd,yudai/etcd,westhood/etcd,chipironcin/etcd,StorReduce/etcd,jchauncey/etcd,betawaffle/etcd,YuleiXiao/etcd,sebrandon1/etcd,bluebreezecf/etcd,combk8s/etcd,msanterre/etcd,wantonsolutions/dinv-etcd,cchamplin/etcd,asim/etcd,asim/etcd,a-robinson/etcd,gae123/etcd,Timer/etcd,Timer/etcd,hongbinz/etcd,linuxcer/etcd,yyljlyy/etcd,gouyang/etcd,lorneli/etcd,freeloop1114/etcd,yichengq/etcd,shakefu/etcd,fasaxc/etcd,xiang90/etcd,buaazp/etcd,hongchaodeng/etcd,tamird/etcd,akauppi/etcd,insequent/etcd,qqsun8819/etcd,gyuho/etcd,gyuho/etcd,Winslett/etcd,pauldallen/etcd,bluebreezecf/etcd,onlyjob/etcd,jeremyeder/etcd,hroyrh/etcd,delkyd/etcd,mkumatag/etcd,sofuture/etcd,purpleidea/etcd,kkaneda/etcd,jlamillan/etcd,chenbaihu/etcd,xdlinear/etcd,jchauncey/etcd,ravigadde/etcd,ktateish/etcd,handsomesun/etcd,hongbinz/etcd,endocode/etcd,xychu/etcd,msanterre/etcd,sinsharat/etcd,linuxcer/etcd,beni55/etcd,coreos/etcd,luxas/etcd,sayden/etcd,rchicoli/etcd,zaphod-concur/etcd,wowsoso/etcd,beni55/etcd,etcd-io/etcd,glycerine/etcd,cognusion/etcd,gityf/etcd,jonboulle/etcd,dnaeon/etcd,yyljlyy/etcd,armstrongli/etcd,ravigadde/etcd,whuwxl/etcd,rnaveiras/etcd,HideoYamauchi/etcd,swingbach/etcd,onlyjob/etcd,joshix/etcd,li-ang/etcd,mike-lerch/etcd,delkyd/etcd,sinsharat/etcd,dannysauer/etcd,fgbreel/etcd,YuleiXiao/etcd,sebrandon1/etcd,li-ang/etcd,a-robinson/etcd,giantswarm/etcd,dannysauer/etcd,CrazyJvm/etcd,iamqizhao/etcd,insequent/etcd,buaazp/etcd,mkumatag/etcd,jlamillan/etcd,shawnps/etcd,fasaxc/etcd,jefby/etcd,swingbach/etcd,shawnps/etcd,armstrongli/etcd,akauppi/etcd,improbable-io/etcd,xychu/etcd,achanda/etcd,arthurcolle/etcd,nekto0n/etcd,imzhulei/etcd,heyitsanthony/etcd,honeyqa/etcd,TheHippo/etcd,Eagle-X/etcd,arthurcolle/etcd,joshix/etcd,mqliang/etcd,vimalk78/etcd,siddontang/etcd,xdlinear/etcd,wowsoso/etcd,xiang90/etcd,sofuture/etcd,hongchaodeng/etcd,gityf/etcd,mike-lerch/etcd,fanminshi/etcd,TheHippo/etcd,westhood/etcd,oscarrr110/etcd,bdarnell/etcd,vimalk78/etcd,glycerine/etcd,mqliang/etcd,lorneli/etcd,jefby/etcd,endocode/etcd,improbable-io/etcd,zaphod-concur/etcd,freeloop1114/etcd