Bump urllib3 from 1.26.5 to 1.26.18 in /easyci2/flask

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.5 to 1.26.18.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.26.5...1.26.18)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

easyci2/flask/requirements.txt

@@ -36,7 +36,7 @@ responses==0.13.2
 retrying==1.3.3
 six==1.14.0
 toml==0.10.2
-urllib3==1.26.5
+urllib3==1.26.18
 webencodings==0.5.1
 Werkzeug==1.0.1
 cachetools==4.2.4