Handle cases where a to/cc field is absent on a status

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -239,9 +239,11 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
       activity in query,
       join: sender in User,
       on: sender.ap_id == activity.actor,
+      # Are non-direct statuses with no to/cc possible?
       where:
-        fragment("not data->'to' \\? ?", ^public) and fragment("not data->'cc' \\? ?", ^public) and
-          fragment("not data->'to' \\? ?", sender.follower_address)
+        fragment("not coalesce(data->'to' \\? ?, false)", ^public) and
+          fragment("not coalesce(data->'cc' \\? ?, false)", ^public) and
+          fragment("not coalesce(data->'to' \\? ?, false)", sender.follower_address)
     )
   end