django2.2: relpace django.core.urlresolvers by django.urls

core/models.py

@@ -38,7 +38,7 @@ from django.utils.translation import ugettext_lazy as _
 from django.utils import timezone
 from django.core import validators
 from django.core.exceptions import ValidationError, PermissionDenied
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.conf import settings
 from django.db import transaction
 from django.contrib.staticfiles.storage import staticfiles_storage