Revert "removing all reference to mgmt_host becaues we are using build to run CS"

Let's reuse the mgmt host for seeding systemvm template to secnodary
storage

This reverts commit 6a9cb033db1393dff79da099ef1e062d5e78ffbe.
use mgmt-host only for seeding template

all other checks for opening ports and listening services are
unnecessary.