Allow moderators to delete posts.

lib/pleroma/web/common_api/common_api.ex

@@ -8,7 +8,7 @@ defmodule Pleroma.Web.CommonAPI do
   def delete(activity_id, user) do
     with %Activity{data: %{"object" => %{"id" => object_id}}} <- Repo.get(Activity, activity_id),
          %Object{} = object <- Object.get_by_ap_id(object_id),
-           true <- user.ap_id == object.data["actor"],
+           true <- user.info["is_moderator"] || (user.ap_id == object.data["actor"]),
          {:ok, delete} <- ActivityPub.delete(object) do
       {:ok, delete}
     end