remove obsolete parameter from users api

lib/api/users.rb

@@ -47,7 +47,6 @@ module API
           optional :external, type: Boolean, desc: 'Flag indicating the user is an external user'
           optional :avatar, type: File, desc: 'Avatar image for user'
           optional :private_profile, type: Boolean, desc: 'Flag indicating the user has a private profile'
-          optional :min_access_level, type: Integer, values: Gitlab::Access.all_values, desc: 'Limit by minimum access level of authenticated user'
           all_or_none_of :extern_uid, :provider
         end