Actually fix upload limit on OTP releases

Closes #1109

CHANGELOG.md

@@ -120,6 +120,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - MRF: `Delete` activities being exempt from MRF policies
 - OTP releases: Not being able to configure OAuth expired token cleanup interval
 - OTP releases: Not being able to configure HTML sanitization policy
+- OTP releases: Not being able to change upload limit (again)
 - Favorites timeline now ordered by favorite date instead of post date
 <details>
   <summary>API Changes</summary>

lib/pleroma/plugs/parsers_plug.ex

@@ -1,21 +0,0 @@
-# Pleroma: A lightweight social networking server
-# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
-# SPDX-License-Identifier: AGPL-3.0-only
-
-defmodule Pleroma.Plugs.Parsers do
-  @moduledoc "Initializes Plug.Parsers with upload limit set at boot time"
-
-  @behaviour Plug
-
-  def init(_opts) do
-    Plug.Parsers.init(
-      parsers: [:urlencoded, :multipart, :json],
-      pass: ["*/*"],
-      json_decoder: Jason,
-      length: Pleroma.Config.get([:instance, :upload_limit]),
-      body_reader: {Pleroma.Web.Plugs.DigestPlug, :read_body, []}
-    )
-  end
-
-  defdelegate call(conn, opts), to: Plug.Parsers
-end

lib/pleroma/web/endpoint.ex

@@ -61,7 +61,17 @@ defmodule Pleroma.Web.Endpoint do
   plug(Plug.RequestId)
   plug(Plug.Logger, log: :debug)
 
-  plug(Pleroma.Plugs.Parsers)
+  plug(Plug.Parsers,
+    parsers: [
+      :urlencoded,
+      {:multipart, length: {Pleroma.Config, :get, [[:instance, :upload_limit]]}},
+      :json
+    ],
+    pass: ["*/*"],
+    json_decoder: Jason,
+    length: Pleroma.Config.get([:instance, :upload_limit]),
+    body_reader: {Pleroma.Web.Plugs.DigestPlug, :read_body, []}
+  )
 
   plug(Plug.MethodOverride)
   plug(Plug.Head)