workaround for Reproducible Builds

[hboutemy]

XBean Spring produces non reproducible output, as seen when rebuilding Mina releases https://github.com/jvm-repo-rebuild/reproducible-central/blob/master/content/org/apache/mina/README.md

waiting for XBean to fix the issue, we can do a workaround: detect and remove the timestamp

then next Mina release will be fully Reproducible