CHANGELOG-4.0: deprecate v2 proxy

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

CHANGELOG-4.0.md

@@ -1,6 +1,6 @@
 
 
-See this more of breaking change wishlists.
+Breaking change wishlists.
 
 
 ## v4.0.0 (TBD)
@@ -14,8 +14,9 @@ See [code changes](https://github.com/coreos/etcd/compare/v3.3.0...v4.0.0) and [
   - Previously, `{"health":"true"}`.
   - Now, `{"health":true}`.
   - Breaks [Kubernetes `kubectl get componentstatuses` command](https://github.com/kubernetes/kubernetes/issues/58240).
+- Deprecate [`etcd --proxy*`](TODO) flags; **no more v2 proxy**.
 - Deprecate [v2 storage backend](https://github.com/coreos/etcd/issues/9232).
-  - v2 API is still supported via [v2 emulation]().
+  - v2 API is still supported via [v2 emulation](TODO).
 - `clientv3.Client.KeepAlive(ctx context.Context, id LeaseID) (<-chan *LeaseKeepAliveResponse, error)` is now [`clientv4.Client.KeepAlive(ctx context.Context, id LeaseID) <-chan *LeaseKeepAliveResponse`](TODO).
   - Similar to `Watch`, [`KeepAlive` does not return errors](https://github.com/coreos/etcd/issues/7488).
   - If there's an unknown server error, kill all open channels and create a new stream on the next `KeepAlive` call.