Bug#906808: libbuild-helper-maven-plugin-java: Provide debian version for maven artefact

[Emmanuel Bourg]

Hi Adrian,

Maven plugins can't use a generic 'debian' version because Maven checks
the actual version in the plugin metadata. If your package doesn't build
with the plugin provided by libbuild-helper-maven-plugin-java you have
to adapt your build. Typically, not specifying the version of the plugin
in the pom.xml file will fix the issue.

Emmanuel Bourg