Bump urllib3 from 1.25.10 to 1.26.5

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.25.10 to 1.26.5.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](https://github.com/urllib3/urllib3/compare/1.25.10...1.26.5)

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

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

requirements.txt

@@ -36,7 +36,7 @@ six==1.15.0
 sqlparse==0.3.1
 Twisted==20.3.0
 txaio==20.4.1
-urllib3==1.25.10
+urllib3==1.26.5
 uvicorn==0.11.8
 uvloop==0.14.0
 websockets==8.1