Clarifies CHANGELOG entry for #13

Author: weierophinney

CHANGELOG.md

@@ -22,7 +22,10 @@ All notable changes to this project will be documented in this file, in reverse
 
 ### Fixed
 
-- [#13](https://github.com/zendframework/zend-expressive-authentication/pull/13) fixes "Trying to get property of non-object" when no record found at PdoDatabase user repository.
+- [#13](https://github.com/zendframework/zend-expressive-authentication/pull/13)
+  fixes an issue whereby fetching a record by an unknown username resulted in a
+  "Trying to get property of non-object" error when using the `PdoDatabase` user
+  repository implementation.
 
 ## 0.2.0 - 2017-11-27