CLOUDSTACK-3870 [VMware] Management traffic network over a VLAN is not working

CLOUDSTACK-3437 In case of multiple physical network setup we see log message "can't get physical network"

CloudStack's control network is management network in case of VMware.
Processing management VLAN id provided in zone traffic label for management traffic.`

Signed-off-by: Sateesh Chodapuneedi <sateesh@apache.org>