Bumps [django](https://github.com/django/django) from 2.2.1 to 2.2.4.
- [Release notes](https://github.com/django/django/releases)
- [Commits](https://github.com/django/django/compare/2.2.1...2.2.4)
Signed-off-by: dependabot[bot] <support@github.com>