Allow for extraConfig to be passed through to CoreOS VMs
Two simple line changes allow for the extraConfig from userdata to be passed through to fog-vsphere vm_clone.
This adds the option to pass through guestinfo network configuration for CoreOS VMs.
With the use of Omaha or similar tools even building the ignition configuration and passing it to the VM on clone is an option.
Without this change an additional tool has to be used to supply the guestinfo before the machine is started for the first time.