Update CHANGELOG.md

CHANGELOG.md

@@ -13,6 +13,7 @@ BUG FIXES:
 * api: fix panic in 'consul acl set-agent-token' [[GH-5533](https://github.com/hashicorp/consul/issues/5533)]
 * acl: memdb filter of tokens-by-policy was inverted [[GH-5575](https://github.com/hashicorp/consul/issues/5575)]
 * acl: Fix legacy rules translation for JSON based rules. [[GH-5493](https://github.com/hashicorp/consul/issues/5493)]
+* agent: Fixed a bug causing RPC errors when the `discovery_max_stale` time was exceeded. [[GH-4673](https://github.com/hashicorp/consul/issues/4673)]
 * connect: fix an issue where Envoy woudl fail to bootstrap if some upstreams were unavailable [[GH-5499](https://github.com/hashicorp/consul/pull/5499)]
 * connect: fix an issue where health checks on proxies might be missed by watchers of `/health/service/:service` API [[GH-5506](https://github.com/hashicorp/consul/issues/5506)]
 * logger: fix an issue where the `log-file` option was not respecting the `log-level` [[GH-4778](https://github.com/hashicorp/consul/issues/4778)]