Merge branch '1866-last-status-stuff' into 'develop'

Resolve "/api/v1/conversations returns the wrong `last_status`"

Closes #1866

See merge request pleroma/pleroma!2647

test/web/mastodon_api/views/conversation_view_test.exs

@@ -15,8 +15,17 @@ defmodule Pleroma.Web.MastodonAPI.ConversationViewTest do
     user = insert(:user)
     other_user = insert(:user)
 
+    {:ok, parent} = CommonAPI.post(user, %{status: "parent"})
+
     {:ok, activity} =
-      CommonAPI.post(user, %{status: "hey @#{other_user.nickname}", visibility: "direct"})
+      CommonAPI.post(user, %{
+        status: "hey @#{other_user.nickname}",
+        visibility: "direct",
+        in_reply_to_id: parent.id
+      })
+
+    {:ok, _reply_activity} =
+      CommonAPI.post(user, %{status: "hu", visibility: "public", in_reply_to_id: parent.id})
 
     [participation] = Participation.for_user_with_last_activity_id(user)