yocto.groovy: port json2junit fix
yocto.groovy: port json2junit fix

Fix for unit tests made in @8207109c4c41c was lost during the Vagrant
to Docker migration in @bc75e1e506dedb.

Signed-off-by: Oleksandr Kravchuk <da66fcdb9815331ae441a2bc352cef73cf081e1e@pelagicore.com>

Pelagicore/pelux-manifests,sashko/pelux-manifests