rafthttp: avoid TestStream to use outdated stream
rafthttp: avoid TestStream to use outdated stream

The original test code before fb4b0b5cf075212f79fcdfa58533915a29c0912d
doesn't work because reader side may update the
stream, while writer side writes message to the old stream and fails.

This PR removes unnecessary call to set term, and avoids this problem to
happen on term > 1 in the future.

jravetch/etcd,offscale/etcd,devfreesg/etcd,hongchaodeng/etcd,glycerine/etcd,xdlinear/etcd,SivagnanamCiena/etcd,spacejam/etcd,coreos/etcd,offscale/etcd,rnaveiras/etcd,siddontang/etcd,QuantiumTechnology/etcd,kkaneda/etcd,chipironcin/etcd,Winslett/etcd,pauldallen/etcd,imzhulei/etcd,kingland/etcd,gouyang/etcd,cchamplin/etcd,endocode/etcd,snailwalker/etcd,wfxiang08/etcd,pengzj/etcd,ajityagaty/etcd,whuwxl/etcd,plasticbox/etcd,es-chow/etcd,steveeJ/etcd,tempbottle/etcd,njharman/etcd,purpleidea/etcd,mitake/etcd,tempbottle/etcd,Winslett/etcd,tguangch/etcd,xychu/etcd,Eagle-X/etcd,yyljlyy/etcd,axingblog/etcd,purpleidea/etcd,insionng/etcd,tamird/etcd,betawaffle/etcd,ajityagaty/etcd,crandles/etcd,snailwalker/etcd,steveeJ/etcd,a-robinson/etcd,Timer/etcd,zaphod-concur/etcd,buaazp/etcd,raoofm/etcd,bspline/etcd,mike-lerch/etcd,jefby/etcd,sinsharat/etcd,olark/etcd,gtank/etcd,openedbox/etcd,xdlinear/etcd,youxidev/etcd,lzbgt/etcd,mqliang/etcd,cognusion/etcd,sebschrader/etcd,jchauncey/etcd,sebschrader/etcd,gityf/etcd,insionng/etcd,HideoYamauchi/etcd,TheHippo/etcd,improbable-io/etcd,beni55/etcd,shawnps/etcd,xueshanf/etcd,gtank/etcd,vimalk78/etcd,gae123/etcd,jlamillan/etcd,dalanlan/etcd,jonboulle/etcd,ktateish/etcd,westhood/etcd,chipironcin/etcd,imzhulei/etcd,hroyrh/etcd,wantonsolutions/dinv-etcd,svdata/etcd,yichengq/etcd,lorneli/etcd,yudai/etcd,hroyrh/etcd,hzy001/etcd,polvi/etcd,ravigadde/etcd,oscarrr110/etcd,fanminshi/etcd,jefby/etcd,rnaveiras/etcd,elimisteve/etcd,sofuture/etcd,csuideal/etcd,njucslqq/etcd,heyitsanthony/etcd,njharman/etcd,bspline/etcd,gityf/etcd,bdarnell/etcd,cognusion/etcd,dnaeon/etcd,glycerine/etcd,CrazyJvm/etcd,xueshanf/etcd,achanda/etcd,YuleiXiao/etcd,xychu/etcd,sinsharat/etcd,handsomesun/etcd,li-ang/etcd,jravetch/etcd,gyuho/etcd,qiaochao911/etcd,rchicoli/etcd,shafreeck/etcd,insequent/etcd,lumjjb/etcd,devfreesg/etcd,tamird/etcd,wowsoso/etcd,TheHippo/etcd,kkaneda/etcd,hongchaodeng/etcd,barakmich/etcd,jmptrader/etcd,onlyjob/etcd,a-robinson/etcd,tguangch/etcd,cockroachdb/etcd,csuideal/etcd,sayden/etcd,princeqjzh/etcd,chenbaihu/etcd,asim/etcd,jlamillan/etcd,honeyqa/etcd,achanda/etcd,shafreeck/etcd,westhood/etcd,tangkun75/etcd,sayden/etcd,mickep76/etcd,joshix/etcd,ylong/etcd,fasaxc/etcd,dalanlan/etcd,barakmich/etcd,li-ang/etcd,junxu/etcd,njucslqq/etcd,betawaffle/etcd,freeloop1114/etcd,raoofm/etcd,olark/etcd,etcd-io/etcd,insequent/etcd,princeqjzh/etcd,buaazp/etcd,SivagnanamCiena/etcd,mkumatag/etcd,mkumatag/etcd,spacejam/etcd,QuantiumTechnology/etcd,YuleiXiao/etcd,giantswarm/etcd,glevand/coreos--etcd,OyTao/etcd_learning,StorReduce/etcd,youxidev/etcd,lzbgt/etcd,freeloop1114/etcd,iamqizhao/etcd,bluebreezecf/etcd,cchamplin/etcd,shakefu/etcd,tangkun75/etcd,plasticbox/etcd,ajityagaty/etcd,arthurcolle/etcd,nkhare/etcd,fasaxc/etcd,jeremyeder/etcd,delkyd/etcd,luxas/etcd,iamqizhao/etcd,nkhare/etcd,bdarnell/etcd,improbable-io/etcd,qiaochao911/etcd,junxu/etcd,visheshnp/etcd,wowsoso/etcd,beni55/etcd,gae123/etcd,ktateish/etcd,pengzj/etcd,wantonsolutions/dinv-etcd,rchicoli/etcd,yyljlyy/etcd,msanterre/etcd,mqliang/etcd,linuxcer/etcd,es-chow/etcd,coreos/etcd,yudai/etcd,kingland/etcd,dnaeon/etcd,xebitstudios/etcd,fanminshi/etcd,mike-lerch/etcd,Timer/etcd,axingblog/etcd,xiang90/etcd,combk8s/etcd,nekto0n/etcd,swingbach/etcd,qqsun8819/etcd,cockroachdb/etcd,visheshnp/etcd,glevand/coreos--etcd,StorReduce/etcd,onlyjob/etcd,swingbach/etcd,qqsun8819/etcd,shakefu/etcd,endocode/etcd,fgbreel/etcd,sebrandon1/etcd,zaphod-concur/etcd,armstrongli/etcd,mkumatag/etcd,dannysauer/etcd,joshix/etcd,shawnps/etcd,msanterre/etcd,siddontang/etcd,xiang90/etcd,crandles/etcd,CrazyJvm/etcd,linuxcer/etcd,armstrongli/etcd,svdata/etcd,honeyqa/etcd,Yhgenomics/etcd,lumjjb/etcd,luxas/etcd,Eagle-X/etcd,yichengq/etcd,bluebreezecf/etcd,Yhgenomics/etcd,asim/etcd,chenbaihu/etcd,OyTao/etcd_learning,polvi/etcd,combk8s/etcd,jeremyeder/etcd,hzy001/etcd,mqliang/etcd,nekto0n/etcd,akauppi/etcd,sebrandon1/etcd,fgbreel/etcd,etcd-io/etcd,giantswarm/etcd,sofuture/etcd,mickep76/etcd,jchauncey/etcd,wantonsolutions/dinv-etcd,jmptrader/etcd,wfxiang08/etcd,lorneli/etcd,dannysauer/etcd,gyuho/etcd,heyitsanthony/etcd,fasaxc/etcd,mitake/etcd,HideoYamauchi/etcd,rnaveiras/etcd,vimalk78/etcd,akauppi/etcd,hongbinz/etcd,delkyd/etcd,openedbox/etcd,gouyang/etcd,xebitstudios/etcd,ylong/etcd,handsomesun/etcd,jonboulle/etcd,elimisteve/etcd,arthurcolle/etcd,ravigadde/etcd,whuwxl/etcd,pauldallen/etcd,etcd-io/etcd,hongbinz/etcd,oscarrr110/etcd