[maven-release-plugin] prepare release docker-workflow-1.9
[maven-release-plugin] prepare release docker-workflow-1.9

jenkinsci/docker-workflow-plugin,cyrille-leclerc/docker-workflow-plugin,jenkinsci/docker-workflow-plugin,rsandell/docker-workflow-plugin,cyrille-leclerc/docker-workflow-plugin,rsandell/docker-workflow-plugin,cyrille-leclerc/docker-workflow-plugin