Bump rails-ujs from 5.2.3 to 5.2.4 (#12526)

Bumps [rails-ujs](https://github.com/rails/rails) from 5.2.3 to 5.2.4.
- [Release notes](https://github.com/rails/rails/releases)
- [Commits](https://github.com/rails/rails/compare/v5.2.3...v5.2.4

)

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