uc-snapshot: use puddle datecode from undercloud
uc-snapshot: use puddle datecode from undercloud

virthost is not expected to have puddle deployed
that is just workaround for 7.2 ipxe-roms-qemu atm

Change-Id: I09e93903c86e348ba25d4de597fbd6c6f0728623

okolisny/InfraRed,redhat-openstack/infrared,okolisny/InfraRed,okolisny/InfraRed,redhat-openstack/infrared,redhat-openstack/infrared