Update django-formtools requirement from ~=2.3 to ~=2.4
Update django-formtools requirement from ~=2.3 to ~=2.4

Updates the requirements on [django-formtools](https://github.com/jazzband/django-formtools) to permit the latest version.
- [Release notes](https://github.com/jazzband/django-formtools/releases)
- [Changelog](https://github.com/jazzband/django-formtools/blob/master/docs/changelog.rst)
- [Commits](https://github.com/jazzband/django-formtools/compare/2.3...2.4)

---
updated-dependencies:
- dependency-name: django-formtools
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
wger-project/wger,wger-project/wger,wger-project/wger,wger-project/wger