Hyper-V: Fixed utilsfactory typo
Hyper-V: Fixed utilsfactory typo

Removed '' from 'None'. max_version should be None or float, not a string.

Change-Id: I1fa5a7b340d926e152787d8a211a36781dc97656

openstack/compute-hyperv,openstack/compute-hyperv,alexpilotti/compute-hyperv,cloudbase/compute-hyperv,stackforge/compute-hyperv