Use http error code 422 in CheckView when a merge is not possible. Previously the response used the code 500 in this case. This is not useful because it's not an internal server error when the check whether a PDF file can be merged fails because that's the point of the CheckView. The code used now means "Unprocessable Entity" and fits better. Part of mpuls/issue6009

# -*- coding: utf-8 -*-

MAX_CONTENT_LENGTH = 50 * 1024 * 1024  # allow 200 MB upload files

PY3O_UNO_DRIVER = "py3o.renderers.pyuno"
PY3O_UNO_SERVER_HOSTNAME = "localhost"
PY3O_UNO_SERVER_PORT = 2001

DEBUG = True