CHANGELOG: add item for 3.4.27

- embed: fix nil pointer dereference when stopServer

Signed-off-by: Wei Fu <fuweid89@gmail.com>

CHANGELOG/CHANGELOG-3.4.md

@@ -9,6 +9,7 @@ Previous change logs can be found at [CHANGELOG-3.3](https://github.com/etcd-io/
 ### etcd server
 - Fix [corruption check may get a `ErrCompacted` error when server has just been compacted](https://github.com/etcd-io/etcd/pull/16047)
 - Improve [Lease put performance for the case that auth is disabled or the user is admin](https://github.com/etcd-io/etcd/pull/16020)
+- Fix [embed: nil pointer dereference when stopServer](https://github.com/etcd-io/etcd/pull/16195)
 
 ### etcdctl v3
 - Add [optional --bump-revision and --mark-compacted flag to etcdctl snapshot restore operation](https://github.com/etcd-io/etcd/pull/16193).