Merge branch 'depracated-migration-inheritance' into 'master'

ActiveRecord::Migration -> ActiveRecord::Migration[5.0] for ImportCommonMetricsNginxVts

See merge request gitlab-org/gitlab-ce!23910

changelogs/unreleased/depracated-migration-inheritance.yml

+---
+title: ActiveRecord::Migration -> ActiveRecord::Migration[5.0]
+merge_request: 23910
+author: Jasper Maes
+type: other

db/migrate/20181006004100_import_common_metrics_nginx_vts.rb

-class ImportCommonMetricsNginxVts < ActiveRecord::Migration
+class ImportCommonMetricsNginxVts < ActiveRecord::Migration[5.0]
   include Gitlab::Database::MigrationHelpers
 
   require Rails.root.join('db/importers/common_metrics_importer.rb')