Bump urllib3 from 1.26.18 to 1.26.19 in /server/backup

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/main/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: server/backup/requirements.txt

@@ -23,4 +23,4 @@ requests==2.32.2
 rsa==4.8
 six==1.16.0
 uritemplate==4.1.1
-urllib3==1.26.18
+urllib3==1.26.19