Remove suffix from mgmt address taken from the ComputerResource conf

This parameter is used by ovirt-node and should include only fqdn or ip4
addr with port number or without. For example 10.35.1.85:8080

Change-Id: I5a40ca0b4870d1955b01d18c88df467b8da35fc4
Signed-off-by: Yaniv Bronhaim <ybronhei@redhat.com>