Bump django from 3.0.14 to 3.1.9 in /apiserver

Bumps [django](https://github.com/django/django) from 3.0.14 to 3.1.9.
- [Release notes](https://github.com/django/django/releases)
- [Commits](https://github.com/django/django/compare/3.0.14...3.1.9)

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

Signed-off-by: dependabot[bot] <support@github.com>

apiserver/requirements.txt

@@ -7,7 +7,7 @@ certifi==2019.11.28
 cffi==1.13.2
 chardet==3.0.4
 defusedxml==0.6.0
-Django==3.0.14
+Django==3.1.9
 django-allauth==0.41.0
 django-rest-auth==0.9.5
 django-simple-history==2.8.0