Partially restore `/api/statusnet/config.json`

lib/pleroma/web/router.ex

@@ -482,6 +482,9 @@ defmodule Pleroma.Web.Router do
     pipe_through(:config)
 
     get("/pleroma/frontend_configurations", TwitterAPI.UtilController, :frontend_configurations)
+
+    # Deprecated
+    get("/statusnet/config", TwitterAPI.UtilController, :config)
   end
 
   scope "/api", Pleroma.Web do

lib/pleroma/web/twitter_api/controllers/util_controller.ex

@@ -88,6 +88,18 @@ def notifications_read(%{assigns: %{user: user}} = conn, %{"id" => notification_
     end
   end
 
+  # Deprecated in favor of `/nodeinfo`
+  # https://git.pleroma.social/pleroma/pleroma/-/merge_requests/2327
+  # https://git.pleroma.social/pleroma/pleroma-fe/-/merge_requests/1084
+  def config(conn, _params) do
+    json(conn, %{
+      site: %{
+        textlimit: to_string(Config.get([:instance, :limit])),
+        vapidPublicKey: Keyword.get(Pleroma.Web.Push.vapid_config(), :public_key)
+      }
+    })
+  end
+
   def frontend_configurations(conn, _params) do
     config =
       Pleroma.Config.get(:frontend_configurations, %{})