Update CHANGELOG

CHANGELOG

@@ -20,8 +20,8 @@ v 8.10.0 (unreleased)
 v 8.9.3 (unreleased)
   - Decreased min width of screen to 1280px for pinned sidebar
   - Fix encrypted data backwards compatibility after upgrading attr_encrypted gem
-v 8.9.3
   - Update mobile button icons to be more inline with typical UI paradigms
+  - Fixes missing avatar on system notes. !4954
 v 8.9.2
   - Fix visibility of snippets when searching.