netutil: test schemes for URLStringsEqual
netutil: test schemes for URLStringsEqual

add tests for http/https mismatch and unix scheme

xiang90/etcd,visheshnp/etcd,bdarnell/etcd,sinsharat/etcd,a-robinson/etcd,cockroachdb/etcd,ajityagaty/etcd,joshix/etcd,bluebreezecf/etcd,heyitsanthony/etcd,glevand/coreos--etcd,whuwxl/etcd,akauppi/etcd,fanminshi/etcd,rnaveiras/etcd,vimalk78/etcd,mkumatag/etcd,mickep76/etcd,bluebreezecf/etcd,xiang90/etcd,sebrandon1/etcd,heyitsanthony/etcd,etcd-io/etcd,a-robinson/etcd,li-ang/etcd,mkumatag/etcd,lorneli/etcd,mickep76/etcd,ajityagaty/etcd,vimalk78/etcd,dannysauer/etcd,rnaveiras/etcd,mkumatag/etcd,dannysauer/etcd,YuleiXiao/etcd,joshix/etcd,li-ang/etcd,fanminshi/etcd,gyuho/etcd,mqliang/etcd,YuleiXiao/etcd,akauppi/etcd,rnaveiras/etcd,ajityagaty/etcd,mqliang/etcd,bdarnell/etcd,etcd-io/etcd,gyuho/etcd,etcd-io/etcd,coreos/etcd,sinsharat/etcd,visheshnp/etcd,mqliang/etcd,glevand/coreos--etcd,cockroachdb/etcd,sebrandon1/etcd,coreos/etcd,whuwxl/etcd,lorneli/etcd