Do recursive fetching in-band for now.

This is to prevent conversation id problems.

lib/pleroma/web/ostatus/ostatus.ex

@@ -124,7 +124,7 @@ defmodule Pleroma.Web.OStatus do
     if !Object.get_cached_by_ap_id(inReplyTo) do
       inReplyToHref = string_from_xpath("//thr:in-reply-to[1]/@href", entry)
       if inReplyToHref do
-        Task.start(fn -> fetch_activity_from_html_url(inReplyToHref) end)
+        fetch_activity_from_html_url(inReplyToHref)
       end
     end