Fix rubocop failure in old glitch-soc migration

db/migrate/20171210213213_add_local_only_flag_to_statuses.rb

@@ -2,6 +2,6 @@
 
 class AddLocalOnlyFlagToStatuses < ActiveRecord::Migration[5.1]
   def change
-    add_column :statuses, :local_only, :boolean
+    add_column :statuses, :local_only, :boolean # rubocop:disable Rails/ThreeStateBooleanColumn
   end
 end