xVMHyperV - Absent VM still tested for Vhd existence

[FLeven]

Created a VHD -> Disc1
Created a VM -> VM1

Set VHD "Disc1" to 'Absent'
Set VM "VM1" to 'Absent

Everything ist removed, but you will get an error everytime the configuration is started/updated:

PowerShell DSC-Ressource "MSFT_xVMHyperV" Function "Test-TargetResource"

Error: "Vhd 'C:\Hyper-V\Virtual Hard Disks\localhost-OSDisk.vhdx' does not exist."
+ CategoryInfo : InvalidOperation: (:) [], CimException
+ FullyQualifiedErrorId : ProviderOperationExecutionFailure

I used the current release version on win10 - 1709

Test for "Absent" resources, should not be needed.