upgrade to new pretix, remove download, add page links

pretix_digital_items/urls.py

@@ -1,9 +1,9 @@
-from django.conf.urls import url
+from django.urls import re_path
 
 from .views import SettingsView
 
 urlpatterns = [
-    url(
+    re_path(
         r"^control/event/(?P<organizer>[^/]+)/(?P<event>[^/]+)/pretix_digital_items/settings",
         SettingsView.as_view(),
         name="settings",