Fix migrating from upstream to glitch-soc messing with hide_notifications mute settings (#2164)

db/migrate/20170716191202_add_hide_notifications_to_mute.rb

@@ -1,5 +1,15 @@
+require Rails.root.join('lib', 'mastodon', 'migration_helpers')
+
 class AddHideNotificationsToMute < ActiveRecord::Migration[5.1]
-  def change
-    add_column :mutes, :hide_notifications, :boolean, default: false, null: false
+  include Mastodon::MigrationHelpers
+
+  disable_ddl_transaction!
+
+  def up
+    add_column_with_default :mutes, :hide_notifications, :boolean, default: true, allow_null: false
+  end
+
+  def down
+    remove_column :mutes, :hide_notifications
   end
 end