Bump spring-core in /java/gwt/gwt-model
Bump spring-core in /java/gwt/gwt-model

Bumps [spring-core](https://github.com/spring-projects/spring-framework) from 3.2.1.RELEASE to 4.3.21.RELEASE.
- [Release notes](https://github.com/spring-projects/spring-framework/releases)
- [Commits](https://github.com/spring-projects/spring-framework/compare/v3.2.1.RELEASE...v4.3.21.RELEASE)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
OpenDDRmobi/openddr-examples,OpenDDRmobi/openddr-examples,OpenDDRmobi/openddr-examples