Description of problem:

VM Cloning stuck in RestoreInProgress phase when using recently created VM clone as the source:

> $ oc get vmclone
> NAME PHASE SOURCEVIRTUALMACHINE TARGETVIRTUALMACHINE
> testclone Succeeded vm-fedora vm-fedora-clone
> testclone-cloned RestoreInProgress vm-fedora-clone vm-fedora-clone2

There is an error in vmrestore events:
> $ oc describe vmrestore
> .
> Events:
> Type Reason Age From Message
> Warning VirtualMachineRestoreError 49s restore-controller VirtualMachineRestore encountered error Operation cannot be fulfilled on virtualmachines.kubevirt.io "vm-fedora-clone2": the object has been modified; please apply your changes to the latest version and try again
> Warning VirtualMachineRestoreError 45s (x24 over 51s) restore-controller VirtualMachineRestore encountered error error patching VM vm-fedora-clone2: failed to apply patch for VM [
>

{"op": "replace", "path": "/spec/template/spec/domain/devices/interfaces/0/macAddress", "value": ""}

,
>

{"op": "replace", "path": "/spec/template/spec/domain/firmware/serial", "value": "new-serial-new"}

,
>

{"op": "remove", "path": "/metadata/annotations/kubevirt.io~1latest-observed-api-version"}

,
>

{"op": "remove", "path": "/metadata/annotations/kubevirt.io~1storage-observed-api-version"}

,
>

{"op": "remove", "path": "/metadata/annotations/restore.kubevirt.io~1lastRestoreUID"}

,
>

{"op": "replace", "path": "/spec/template/spec/domain/firmware/uuid", "value": ""}

> ]: error in remove for path: '/metadata/annotations/kubevirt.io~1latest-observed-api-version': Unable to remove nonexistent key: kubevirt.io/latest-observed-api-version: missing value

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. create VM
2. Clone VM
3. Clone again using the VM clone as a source

Actual results:
VM cloning failed

Expected results:
VM successfully cloned

Additional info: