Fix failure to serve media from custom upload path

lib/pleroma/upload.ex

@@ -58,7 +58,7 @@ def store(%{"img" => "data:image/" <> image_data}) do
     }
   end
 
-  defp upload_path do
+  def upload_path do
     settings = Application.get_env(:pleroma, Pleroma.Upload)
     Keyword.fetch!(settings, :uploads)
   end

lib/pleroma/web/endpoint.ex

@@ -11,7 +11,7 @@ defmodule Pleroma.Web.Endpoint do
   #
   # You should set gzip to true if you are running phoenix.digest
   # when deploying your static files in production.
-  plug(Plug.Static, at: "/media", from: "uploads", gzip: false)
+  plug(Plug.Static, at: "/media", from: Pleroma.Upload.upload_path(), gzip: false)
 
   plug(
     Plug.Static,