ActivityPub: Use recipients fields.

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -140,11 +140,8 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
   defp restrict_tag(query, _), do: query
 
   defp restrict_recipients(query, recipients) do
-    Enum.reduce(recipients, query, fn (recipient, q) ->
-      map = %{ to: [recipient] }
-      from activity in q,
-      or_where: fragment(~s(? @> ?), activity.data, ^map)
-    end)
+    from activity in query,
+     where: fragment("? && ?", ^recipients, activity.recipients)
   end
 
   defp restrict_local(query, %{"local_only" => true}) do