Bump click from 6.7 to 7.1.2 in /cvat/requirements (#1757)

Bumps [click](https://github.com/pallets/click) from 6.7 to 7.1.2.
- [Release notes](https://github.com/pallets/click/releases)
- [Changelog](https://github.com/pallets/click/blob/master/CHANGES.rst)
- [Commits](https://github.com/pallets/click/compare/6.7...7.1.2)

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

@@ -1,4 +1,4 @@
-click==6.7
+click==7.1.2
 Django==2.2.13
 django-appconf==1.0.4
 django-auth-ldap==2.2.0