Bump urllib3 from 1.26.17 to 1.26.18 in /mysite

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.17 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@1.26.17...1.26.18)

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

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

Author: dependabot[bot]

mysite/requirements.txt

@@ -5,4 +5,4 @@ djangorestframework==3.14.0
 django-sslserver==0.22
 Django==4.2.3
 six==1.15.0
-urllib3===1.26.17 
+urllib3===1.26.18