Bump urllib3[secure] from 1.25.10 to 1.25.11

Bumps [urllib3[secure]](https://github.com/urllib3/urllib3) from 1.25.10 to 1.25.11.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/master/CHANGES.rst)
- [Commits](urllib3/urllib3@1.25.10...1.25.11)

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

requirements/base.txt

@@ -15,7 +15,7 @@ psycopg2-binary==2.8.6
 pytz==2020.1
 static==1.1.1
 whitenoise[brotli]==5.2.0
-urllib3[secure]==1.25.10
+urllib3[secure]==1.25.11
 future==0.18.2
 coreapi==2.3.3
 pygments==2.7.1