Fix OAuth cleanup worker unconditionally starting

!1576 removed enabled/disabled check from the worker, in favor of just
not starting it in application.ex if disabled. However a line
unconditionally starting the worker was removed

lib/pleroma/application.ex

@@ -41,7 +41,6 @@ def start(_type, _args) do
         hackney_pool_children() ++
         [
           Pleroma.Web.Federator.RetryQueue,
-          Pleroma.Web.OAuth.Token.CleanWorker,
           Pleroma.Stats,
           %{
             id: :web_push_init,