[1.4.x] Fixed oversight in e3b6fed3. Refs #20636.

import warnings

from django.conf import settings, UserSettingsHolder

from django.core import mail

from django import http

from django.test.signals import template_rendered, setting_changed

from django.http import request

from django.template import Template, loader, TemplateDoesNotExist

from django.template.loaders import cached

from django.utils.translation import deactivate

    mail._original_email_backend = settings.EMAIL_BACKEND

    settings.EMAIL_BACKEND = 'django.core.mail.backends.locmem.EmailBackend'

    request._original_allowed_hosts = settings.ALLOWED_HOSTS

    http._original_allowed_hosts = settings.ALLOWED_HOSTS

    settings.ALLOWED_HOSTS = ['*']

    mail.outbox = []

    settings.EMAIL_BACKEND = mail._original_email_backend

    del mail._original_email_backend

    settings.ALLOWED_HOSTS = request._original_allowed_hosts

    del request._original_allowed_hosts

    settings.ALLOWED_HOSTS = http._original_allowed_hosts

    del http._original_allowed_hosts

    del mail.outbox