CHANGELOG: add v2 server stat fix

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

CHANGELOG-3.2.md

@@ -7,6 +7,7 @@ See [code changes](https://github.com/coreos/etcd/compare/v3.2.18...v3.2.19) and
 ### Metrics, Monitoring
 
 - Fix [`etcd_debugging_server_lease_expired_total`](https://github.com/coreos/etcd/pull/9557) Prometheus metric.
+- Fix [race conditions in v2 server stat collecting](https://github.com/coreos/etcd/pull/9562).
 
 ### Security, Authentication
 

CHANGELOG-3.3.md

@@ -7,6 +7,7 @@ See [code changes](https://github.com/coreos/etcd/compare/v3.3.3...v3.3.4) and [
 ### Metrics, Monitoring
 
 - Fix [`etcd_debugging_server_lease_expired_total`](https://github.com/coreos/etcd/pull/9557) Prometheus metric.
+- Fix [race conditions in v2 server stat collecting](https://github.com/coreos/etcd/pull/9562).
 
 ### Security, Authentication
 

CHANGELOG-3.4.md

@@ -80,6 +80,7 @@ See [code changes](https://github.com/coreos/etcd/compare/v3.3.0...v3.4.0) and [
 - Add [`etcd_debugging_mvcc_db_total_size_in_use_in_bytes`](https://github.com/coreos/etcd/pull/9256) Prometheus metric.
 - Add missing [`etcd_network_peer_sent_failures_total` count](https://github.com/coreos/etcd/pull/9437).
 - Fix [`etcd_debugging_server_lease_expired_total`](https://github.com/coreos/etcd/pull/9557) Prometheus metric.
+- Fix [race conditions in v2 server stat collecting](https://github.com/coreos/etcd/pull/9562).
 
 ### Security, Authentication