Simplify migration

priv/repo/migrations/20210218223811_add_disclose_client_to_users.exs

 defmodule Pleroma.Repo.Migrations.AddDiscloseClientToUsers do
   use Ecto.Migration
 
-  def up do
+  def change do
     alter table(:users) do
       add(:disclose_client, :boolean, default: true)
     end
   end
-
-  def down do
-    alter table(:users) do
-      remove(:disclose_client)
-    end
-  end
 end