changelog: Mention fixes to +s channel leaks (#1700)

* changelog: Mention fixes to +s channel leaks

* Combining and contextualising for administators

---------

Co-authored-by: Will Hunt <[email protected]>

Author: progval

CHANGELOG.md

@@ -4,7 +4,7 @@
 Bugfixes
 --------
 
-- Fix SQL syntax errors in the PostgreSQL data store. ([\#1660](https://github.com/matrix-org/matrix-appservice-irc/issues/1660))
+- Fix leak of secret channels (name, topic, and member count) to the public room directory due to a regressive refactor in a previous release. ([\#1660](https://github.com/matrix-org/matrix-appservice-irc/issues/1660), [\#1698](https://github.com/matrix-org/matrix-appservice-irc/issues/1698))
 - Fix unlink command showing an error. ([\#1692](https://github.com/matrix-org/matrix-appservice-irc/issues/1692))