Bump urllib3 from 1.25.10 to 1.26.3

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.25.10 to 1.26.3.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/1.26.3/CHANGES.rst)
- [Commits](urllib3/urllib3@1.25.10...1.26.3)

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

requirements.txt

@@ -30,7 +30,7 @@ sqlparse==0.3.1
 toml==0.10.1
 typed-ast==1.4.2
 typing-extensions==3.7.4.3
-urllib3==1.25.10
+urllib3==1.26.3
 webencodings==0.5.1
 wrapt==1.12.1
 xmltodict==0.12.0