Removed duplicated section from CHANGELOG.md

CHANGELOG.md

@@ -658,21 +658,6 @@ entry.
 - Drop feature to take ownership of trigger token.
 
 
-## 11.11.7
-
-### Security (9 changes)
-
-- Restrict slash commands to users who can log in.
-- Patch XSS issue in wiki links.
-- Filter merge request params on the new merge request page.
-- Fix Server Side Request Forgery mitigation bypass.
-- Show badges if pipelines are public otherwise default to project permissions.
-- Do not allow localhost url redirection in GitHub Integration.
-- Do not show moved issue id for users that cannot read issue.
-- Use source project as permissions reference for MergeRequestsController#pipelines.
-- Drop feature to take ownership of trigger token.
-
-
 ## 11.11.4 (2019-06-26)
 
 ### Fixed (3 changes)