Bump urllib3 from 1.25.3 to 1.26.5 in /app

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.25.3 to 1.26.5.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.25.3...1.26.5)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-type: direct:production
...

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

Author: dependabot[bot]

app/requirements.txt

@@ -9,4 +9,4 @@ pytest==5.1.1
 requests==2.22.0
 scikit-learn==0.22.2.post1
 toolz==0.10.0
-urllib3==1.25.3
+urllib3==1.26.5