[libvirt] VirtualBox error message displayed on windows

Hi Matthias, Just came across an interesting (non fatal) bug with the new VirtualBox code on windows. When starting virsh on a windows system that *doesn't* have VirtualBox installed, virsh prints an error to the users terminal about missing VirtualBox registry keys, then continues on with it's intended operation. (screenshot attached) It's not a killer, but the error makes no sense in context when I'm (for example) trying to connect to a remote qemu box. Heh. Feel inclined to write a patch for it? Regards and best wishes, Justin Clift