Fix CSRF error on login

[AndyRae]

Changes

Fixes a bug after updating to Django 4.2 in #640, a user could not log in to a deployed instance of the web app.

Crucially a fix needed for Azure web apps: https://stackoverflow.com/questions/66977121/azure-ad-redirect-uri-changes-from-https-to-http

Checks

Important: please complete these before merging.

• [x] Run migrations, if any.
• [x] Update changelog.md, including migration instructions if any.
• [x] Run unit tests.

[github-actions[bot]]

Tests	Skipped	Failures	Errors	Time
25	1 :zzz:	0 :x:	0 :fire:	2.247s :stopwatch: