Bump govuk_app_config from 1.16.1 to 1.16.3
Bump govuk_app_config from 1.16.1 to 1.16.3

Bumps [govuk_app_config](https://github.com/alphagov/govuk_app_config) from 1.16.1 to 1.16.3.
- [Release notes](https://github.com/alphagov/govuk_app_config/releases)
- [Changelog](https://github.com/alphagov/govuk_app_config/blob/master/CHANGELOG.md)
- [Commits](https://github.com/alphagov/govuk_app_config/compare/v1.16.1...v1.16.3)
alphagov/bouncer,alphagov/bouncer,alphagov/bouncer