Bump urllib3 from 1.26.18 to 1.26.19

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] <[email protected]>

Author: dependabot[bot]

Diff for: requirements.txt

@@ -1,4 +1,4 @@
-urllib3==1.26.18
+urllib3==1.26.19
 pytz
 accept_types >=0.4.1
 apscheduler==3.6.3