CHANGELOG-3.4: update "golang.org/x/sys" vendor
CHANGELOG-3.4: update "golang.org/x/sys" vendor

Signed-off-by: Gyuho Lee <0fbd30d364d71722b926950b451cecd97b54fc29@amazon.com>

etcd-io/etcd,mkumatag/etcd,dannysauer/etcd,rnaveiras/etcd,gyuho/etcd,cockroachdb/etcd,mkumatag/etcd,li-ang/etcd,etcd-io/etcd,etcd-io/etcd,mkumatag/etcd,rnaveiras/etcd,ajityagaty/etcd,rnaveiras/etcd,coreos/etcd,cockroachdb/etcd,ajityagaty/etcd,coreos/etcd,li-ang/etcd,ajityagaty/etcd,mqliang/etcd,mqliang/etcd,mqliang/etcd,dannysauer/etcd,gyuho/etcd