[#534] Made federation push sender be determined basing on content instead of referer header. Updated tests.

lib/pleroma/web/websub/websub.ex

@@ -278,8 +278,7 @@ defmodule Pleroma.Web.Websub do
              xml,
              [
                {"Content-Type", "application/atom+xml"},
-               {"X-Hub-Signature", "sha1=#{signature}"},
-               {"referer", Pleroma.Web.Endpoint.url()}
+               {"X-Hub-Signature", "sha1=#{signature}"}
              ]
            ) do
       Instances.set_reachable(callback)

lib/pleroma/web/websub/websub_controller.ex

@@ -20,8 +20,6 @@ defmodule Pleroma.Web.Websub.WebsubController do
          ]
   )
 
-  plug(Pleroma.Web.Plugs.SetRequesterReachablePlug when action in [:websub_incoming])
-
   def websub_subscription_request(conn, %{"nickname" => nickname} = params) do
     user = User.get_cached_by_nickname(nickname)