Remove ghec version from repository visibility settings

GHEC has no public repositories

Author: schdief

content/repositories/managing-your-repositorys-settings-and-features/managing-repository-settings/setting-repository-visibility.md

@@ -11,7 +11,6 @@ redirect_from:
 versions:
   fpt: '*'
   ghes: '*'
-  ghec: '*'
 topics:
   - Repositories
 shortTitle: Repository visibility