update CHANGLOG

Signed-off-by: Xiang Dai <764524258@qq.com>

CHANGELOG.md

@@ -29,7 +29,7 @@ We use *breaking* word for marking changes that are not backward compatible (rel
 - [#2049](https://github.com/thanos-io/thanos/pull/2049) Tracing: Support sampling on Elastic APM with new sample_rate setting.
 - [#2008](https://github.com/thanos-io/thanos/pull/2008) Querier, Receiver, Sidecar, Store: Add gRPC [health check](https://github.com/grpc/grpc/blob/master/doc/health-checking.md) endpoints.
 - [#2145](https://github.com/thanos-io/thanos/pull/2145) Tracing: track query sent to prometheus via remote read api.
-- [#2113](https://github.com/thanos-io/thanos/pull/2113) Bucket: Added `thanos bucket replicate` (mixin todo).
+- [#2113](https://github.com/thanos-io/thanos/pull/2113) Bucket: Added `thanos bucket replicate`.
 
 ### Changed