DeleteValidator: Don't federate local deletions of remote objects.

Closes #1497

lib/pleroma/web/activity_pub/pipeline.ex

@@ -29,7 +29,9 @@ defmodule Pleroma.Web.ActivityPub.Pipeline do
 
   defp maybe_federate(activity, meta) do
     with {:ok, local} <- Keyword.fetch(meta, :local) do
-      if local do
+      do_not_federate = meta[:do_not_federate]
+
+      if !do_not_federate && local do
         Federator.publish(activity)
         {:ok, :federated}
       else