Merge branch 'comment-migration-helpers-include' into 'master'

Comment out migration helper include in migration template

See merge request gitlab-org/gitlab!25205

generator_templates/active_record/migration/migration.rb

@@ -4,7 +4,8 @@
 # for more information on how to write migrations for GitLab.
 
 class <%= migration_class_name %> < ActiveRecord::Migration[<%= ActiveRecord::Migration.current_version %>]
-  include Gitlab::Database::MigrationHelpers
+  # Uncomment the following include if you require helper functions:
+  # include Gitlab::Database::MigrationHelpers
 
   # Set this constant to true if this migration requires downtime.
   DOWNTIME = false

generator_templates/rails/post_deployment_migration/migration.rb

@@ -4,7 +4,8 @@
 # for more information on how to write migrations for GitLab.
 
 class <%= migration_class_name %> < ActiveRecord::Migration[<%= ActiveRecord::Migration.current_version %>]
-  include Gitlab::Database::MigrationHelpers
+  # Uncomment the following include if you require helper functions:
+  # include Gitlab::Database::MigrationHelpers
 
   DOWNTIME = false