Bump django from 2.2.5 to 2.2.28 in /services/FileManagement

Bumps [django](https://github.com/django/django) from 2.2.5 to 2.2.28.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@2.2.5...2.2.28)

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

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

services/FileManagement/requirements.txt

@@ -4,7 +4,7 @@ certifi==2019.6.16
 chardet==3.0.4
 cycler==0.10.0
 decorator==4.4.0
-Django==2.2.5
+Django==2.2.28
 django-cors-headers==3.1.0
 djangorestframework==3.10.3
 idna==2.8