Update CHANGELOG for 8.7.7 release

[ci skip]

CHANGELOG

@@ -235,6 +235,9 @@ v 8.8.0
 
 v 8.7.7
   - Fix import by `Any Git URL` broken if the URL contains a space
+  - Prevent unauthorized access to other projects build traces
+  - Forbid scripting for wiki files
+  - Only show notes through JSON on confidential issues that the user has access to
 
 v 8.7.6
   - Fix links on wiki pages for relative url setups. !4131 (Artem Sidorenko)