moved OAuth.Token.CleanWorker to Oban Periodic jobs

lib/pleroma/workers/background_worker.ex

@@ -6,7 +6,6 @@ defmodule Pleroma.Workers.BackgroundWorker do
   alias Pleroma.Activity
   alias Pleroma.User
   alias Pleroma.Web.ActivityPub.MRF.MediaProxyWarmingPolicy
-  alias Pleroma.Web.OAuth.Token.CleanWorker
 
   use Pleroma.Workers.WorkerHelper, queue: "background"
 
@@ -55,10 +54,6 @@ defmodule Pleroma.Workers.BackgroundWorker do
     User.perform(:follow_import, follower, followed_identifiers)
   end
 
-  def perform(%{"op" => "clean_expired_tokens"}, _job) do
-    CleanWorker.perform(:clean)
-  end
-
   def perform(%{"op" => "media_proxy_preload", "message" => message}, _job) do
     MediaProxyWarmingPolicy.perform(:preload, message)
   end

lib/pleroma/workers/cron/clear_oauth_token_worker.ex

@@ -0,0 +1,21 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Workers.Cron.ClearOauthTokenWorker do
+  @moduledoc """
+  The worker to clean an expired oauth tokens.
+  """
+
+  use Oban.Worker, queue: "background"
+
+  alias Pleroma.Config
+  alias Pleroma.Web.OAuth.Token
+
+  @impl Oban.Worker
+  def perform(_opts, _job) do
+    if Config.get([:oauth2, :clean_expired_tokens], false) do
+      Token.delete_expired_tokens()
+    end
+  end
+end