py-django2: updated to 2.2.16

Django 2.2.16 fixes two security issues and two data loss bugs in 2.2.15.

CVE-2020-24583: Incorrect permissions on intermediate-level directories on Python 3.7+

On Python 3.7+, FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files and to intermediate-level collected static directories when using the collectstatic management command.

You should review and manually fix permissions on existing intermediate-level directories.

CVE-2020-24584: Permission escalation in intermediate-level directories of the file system cache on Python 3.7+

On Python 3.7+, the intermediate-level directories of the file system cache had the system窶冱 standard umask rather than 0o077 (no group or others permissions).

Bugfixes

Fixed a data loss possibility in the select_for_update(). When using related fields pointing to a proxy model in the of argument, the corresponding model was not locked.
Fixed a data loss possibility, following a regression in Django 2.0, when copying model instances with a cached fields value.

Django 2.2.15 fixes two bugs in 2.2.14.

Bugfixes

Allowed setting the SameSite cookie flag in HttpResponse.delete_cookie().
Fixed crash when sending emails to addresses with display names longer than 75 chars on Python 3.6.11+, 3.7.8+, and 3.8.4+.


(adam)