Bump urllib3 from 1.26.15 to 1.26.17 in /requirements

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.15 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@1.26.15...1.26.17)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements/requirements.txt

@@ -1,3 +1,3 @@
 requests>=2.22.0
 requests_toolbelt==0.10.1
-urllib3==1.26.15
+urllib3==1.26.17

requirements/test.txt

@@ -4,4 +4,4 @@ coverage==4.5.4
 tox==3.14.2
 responses==0.17.0
 requests_toolbelt==0.10.1
-urllib3==1.26.15
+urllib3==1.26.17