Bump django-bootstrap3 from 12.0.1 to 12.0.3

Bumps [django-bootstrap3](https://github.com/dyve/django-bootstrap3) from 12.0.1 to 12.0.3.
- [Release notes](https://github.com/dyve/django-bootstrap3/releases)
- [Changelog](https://github.com/dyve/django-bootstrap3/blob/master/HISTORY.rst)
- [Commits](zostera/django-bootstrap3@v12.0.1...v12.0.3)

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

requirements/base.txt

@@ -1,5 +1,5 @@
 Django==2.2.8
-django-bootstrap3==12.0.1
+django-bootstrap3==12.0.3
 dj-database-url==0.5.0
 dj-static==0.0.6
 django-csp==3.5