It can be safely removed from the VMX, VMWare will still boot the
machine and once another ethernet is added it is updated in the VMX to
zero. So do not require it and default to zero too since this part of
the XML is done as best effort and it is mentioned even in our
documentation.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>