LDAP auth: update CHANGELOG.md

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ## 3.5.8.dev
+* Extend [auth]: re-factor & overhaul LDPA autrhentication, especially for Python's ldap module
 
 ## 3.5.7
 * Extend: [auth] dovecot: add support for version >= 2.4