virtualize.py: set the correct hostname for I-S
virtualize.py: set the correct hostname for I-S

use the propery hostname instead of the hostname+prefix variable.

enovance/infra-virt,goneri/infra-virt,enovance/infra-virt,redhat-cip/infra-virt,goneri/infra-virt,redhat-cip/infra-virt