deposit.urls: Retro-compatibility fix about import and type conflict

We now type this module with django version which allows us to.

This fixes the debian buster build [1]

[1] https://jenkins.softwareheritage.org/job/debian/job/packages/job/DDEP/job/gbp-buildpackage/94/consoleFull

Closes T3072

swh/deposit/urls.py

-# Copyright (C) 2017-2019  The Software Heritage developers
+# Copyright (C) 2017-2021  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -6,15 +6,24 @@
 """SWH's main deposit URL Configuration
 
 """
+from __future__ import annotations
 
 from typing import Sequence, Union
 
 from django.conf.urls import include, url
 from django.shortcuts import render
-from django.urls import URLPattern, URLResolver
 from django.views.generic.base import RedirectView
 from rest_framework.urlpatterns import format_suffix_patterns
 
+try:
+    from django.urls import URLPattern, URLResolver
+except ImportError:
+    # retro-compatibility workaround, django 1.11.29 [1] does not expose the previous
+    # module, so we fallback to no typing for such version.
+    # [1] django debian stable version: 1:1.11.29-1~deb10u1
+    pass
+
+
 favicon_view = RedirectView.as_view(
     url="/static/img/icons/swh-logo-32x32.png", permanent=True
 )

[Phabricator Migration user]

Some references in the commit message have been migrated:

• T3072 is now swh/infra/sysadm-environment#3072 (closed)