Bump urllib3

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.18 to 1.26.19.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/1.26.19/CHANGES.rst)
- [Commits](urllib3/urllib3@1.26.18...1.26.19)

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

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

aws/examples/lambda/additional_files/lambda_function_payload/requirements.txt

@@ -6,4 +6,4 @@ powerline-status==2.7
 python-dateutil==2.8.1
 s3transfer==0.3.3
 six==1.14.0
-urllib3==1.26.18
+urllib3==1.26.19