Fixed gitlab.com importer missing confidential attribute

CHANGELOG

@@ -87,6 +87,7 @@ v 8.11.5 (unreleased)
   - Fix member expiration date picker after update
   - Fix suggested colors options for new labels in the admin area. !6138
   - Fix GitLab import button
+  - Fix confidential issues being exposed as public using gitlab.com export
 
 v 8.11.4
   - Fix resolving conflicts on forks. !6082

lib/gitlab/gitlab_import/importer.rb

@@ -41,7 +41,8 @@ module Gitlab
               title: issue["title"],
               state: issue["state"],
               updated_at: issue["updated_at"],
-              author_id: gl_user_id(project, issue["author"]["id"])
+              author_id: gl_user_id(project, issue["author"]["id"]),
+              confidential: issue["confidential"]
             )
           end
         end

spec/lib/gitlab/gitlab_import/importer_spec.rb

@@ -13,6 +13,7 @@ describe Gitlab::GitlabImport::Importer, lib: true do
           'title' => 'Issue',
           'description' => 'Lorem ipsum',
           'state' => 'opened',
+          'confidential' => true,
           'author' => {
             'id' => 283999,
             'name' => 'John Doe'
@@ -34,6 +35,7 @@ describe Gitlab::GitlabImport::Importer, lib: true do
         title: 'Issue',
         description: "*Created by: John Doe*\n\nLorem ipsum",
         state: 'opened',
+        confidential: true,
         author_id: project.creator_id
       }