It seems that the BNG Blaster is not working with ubuntu 20.04
if qdisc bypass is enabled. Here further investiagtions will follow
but for now qdisc bypass will be disabled by default but can be
enabled with the config option `qdisc-bypass` in the interfaces
section.
Now per default sessions are created by iteration
over inner VLAN range first and outer VLAN second.
Which can be changed by new configuration option
`iterate-vlan-outer` to iterate on outer VLAN first
and inner VLAN second.
