We [used to](https://github.com/cloudogu/spring-petclinic/blob/54d996f4027ed62fb9f485c08b6046d9c60240fa/Jenkinsfile#L93) setup the Cloudogu Ecosystem Nexus as Maven Central mirror. We should restore this behaviour. However, this needs to be provided by ces-build-lib's Maven abstraction, as this is used right now.