etcdserver: let Status() not require authentication
etcdserver: let Status() not require authentication

The information that can be obtained with the RPC doesn't need to be
protected.

Fix https://github.com/coreos/etcd/issues/7721

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