Bump requests from 2.20.0 to 2.23.0 in /cvat/requirements (#1672)

Bumps [requests](https://github.com/psf/requests) from 2.20.0 to 2.23.0.
- [Release notes](https://github.com/psf/requests/releases)
- [Changelog](https://github.com/psf/requests/blob/master/HISTORY.md)
- [Commits](https://github.com/psf/requests/compare/v2.20.0...v2.23.0)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

cvat/requirements/base.txt

@@ -13,7 +13,7 @@ pytz==2018.3
 pyunpack==0.1.2
 rcssmin==1.0.6
 redis==3.2.0
-requests==2.20.0
+requests==2.23.0
 rjsmin==1.0.12
 rq==1.0.0
 rq-scheduler==0.9.1