etcdserver: Fix snapshot always nil
etcdserver: Fix snapshot always nil

etcd-io/etcd,rnaveiras/etcd,rnaveiras/etcd,coreos/etcd,ajityagaty/etcd,mkumatag/etcd,rnaveiras/etcd,coreos/etcd,gyuho/etcd,mqliang/etcd,etcd-io/etcd,mkumatag/etcd,mqliang/etcd,ajityagaty/etcd,gyuho/etcd,mqliang/etcd,etcd-io/etcd,ajityagaty/etcd,mkumatag/etcd