MRF: fix up unserializable option lists in describe implementations

CHANGELOG.md

@@ -42,6 +42,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Pleroma.Upload base_url was not automatically whitelisted by MediaProxy. Now your custom CDN or file hosting will be accessed directly as expected.
 - Report email not being sent to admins when the reporter is a remote user
 - MRF: ensure that subdomain_match calls are case-insensitive
+- MRF: fix use of unserializable keyword lists in describe() implementations
 
 ### Added
 - **Breaking:** MRF describe API, which adds support for exposing configuration information about MRF policies to NodeInfo.

lib/pleroma/web/activity_pub/mrf/hellthread_policy.ex

@@ -92,5 +92,6 @@ def filter(%{"type" => "Create"} = message) do
   def filter(message), do: {:ok, message}
 
   @impl true
-  def describe, do: {:ok, %{mrf_hellthread: Pleroma.Config.get([:mrf_hellthread])}}
+  def describe,
+    do: {:ok, %{mrf_hellthread: Pleroma.Config.get(:mrf_hellthread) |> Enum.into(%{})}}
 end

lib/pleroma/web/activity_pub/mrf/reject_non_public.ex

@@ -46,5 +46,6 @@ def filter(%{"type" => "Create"} = object) do
   def filter(object), do: {:ok, object}
 
   @impl true
-  def describe, do: {:ok, %{mrf_rejectnonpublic: Pleroma.Config.get([:mrf_rejectnonpublic])}}
+  def describe,
+    do: {:ok, %{mrf_rejectnonpublic: Pleroma.Config.get(:mrf_rejectnonpublic) |> Enum.into(%{})}}
 end

lib/pleroma/web/activity_pub/mrf/vocabulary_policy.ex

@@ -32,5 +32,6 @@ def filter(%{"type" => message_type} = message) do
 
   def filter(message), do: {:ok, message}
 
-  def describe, do: {:ok, %{mrf_vocabulary: Pleroma.Config.get(:mrf_vocabulary)}}
+  def describe,
+    do: {:ok, %{mrf_vocabulary: Pleroma.Config.get(:mrf_vocabulary) |> Enum.into(%{})}}
 end