etcdserver: fill-in Auth API Header in apply layer
etcdserver: fill-in Auth API Header in apply layer

Replacing "etcdserver: fill a response header in auth RPCs"
The revision should be set at the time of "apply",
not in later RPC layer.

Fix https://github.com/coreos/etcd/issues/7691

Signed-off-by: Gyu-Ho Lee <3454051ee3341eb69bdf6fca40899cdad4d86496@gmail.com>

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