Allow eth0 in vr-vjunosswitch.go node definition for external communication with fxp0's configured addresses, to make this work with Apstra

[sjohnson1980]

Hi,

As eth0 is blacklisted and fxp0's not part of the list of allowed interfaces either, would it be possible to allow eth0 as a valid interface to be bridged on vjunos-switch and possibly vjunos-router?

The current setup prevents proper interaction with Apstra, for example, as it expects its agent's IP to match the configured management IP on fxp0, which is bound to eth0.

If we can configure eth0, we can bind it to a management bridge in the topology and not rely on docker0 bridge, allowing the use of L2 & L3 connectivity to external systems using the configured IP address.

Thanks!