hide irritating Java Preferences warning on Windows

Change-Id: I599efee4a55888b6d2e2e6b7d7d6807ed5f7e7fd
Reviewed-on: http://gerrit.esdi-community.eu/3162
Tested-by: Jenkins <sitemple@igd.fraunhofer.de>
Reviewed-by: Simon Templer <simon.templer@igd.fraunhofer.de>