Remove reply-to for shares, mastodon gets confused.

lib/pleroma/web/ostatus/activity_representer.ex

@@ -114,7 +114,6 @@ def to_simple_form(%{data: %{"type" => "Announce"}} = activity, user, with_autho
       {:"ostatus:conversation", [], h.(activity.data["context"])},
       {:link, [href: h.(activity.data["context"]), rel: 'ostatus:conversation'], []},
       {:link, [rel: 'self', type: ['application/atom+xml'], href: h.(activity.data["id"])], []},
-      {:"thr:in-reply-to", [ref: to_charlist(activity.data["object"])], []},
       {:"activity:object", retweeted_xml}
     ] ++ mentions ++ author
   end

test/web/ostatus/activity_representer_test.exs

@@ -106,7 +106,6 @@ test "an announce activity" do
     <ostatus:conversation>#{announce.data["context"]}</ostatus:conversation>
     <link href="#{announce.data["context"]}" rel="ostatus:conversation" />
     <link rel="self" type="application/atom+xml" href="#{announce.data["id"]}"/>
-    <thr:in-reply-to ref="#{note.data["object"]["id"]}" />
     <activity:object>
       #{note_xml}
     </activity:object>