Changelog update

Author: naemono

CHANGELOG.md

@@ -4,6 +4,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 This CHANGELOG follows the format located [here](https://github.com/sensu-plugins/community/blob/master/HOW_WE_CHANGELOG.md)
 
 ## [Unreleased]
+### Fixed
+- Ensure Server status/Replicaset stats are current host's, not host from read preference (@naemon)
 
 ## [2.0.1] - 2017-10-19
 ### Fixed