Fix wrong config_drive_cdrom option placement in nova config file

At the moment the option exists in [DEFAULT] config file section,
but as per code [1] it should be in [hyperv] section.
[1] https://github.com/openstack/nova/blob/mitaka-eol/nova/virt/hyperv/vmops.py#L92

Closes-bug: PROD-15110

Change-Id: I17ac59058c8df15e39a282e508a5871e183bb391
2 files changed