Bump urllib3 in /examples/sharedlinks/sharedlinks-backend

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.5 to 1.26.17.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.26.5...1.26.17)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-type: indirect
...

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

examples/sharedlinks/sharedlinks-backend/requirements.txt

@@ -53,5 +53,5 @@ sqlparse==0.4.4
     # via django
 uritemplate==3.0.1
     # via coreapi
-urllib3==1.26.5
+urllib3==1.26.17
     # via requests