Fixes that `containers.<name>.extraVeths.<name>` configuration was not always applied. When configuring `containers.<name>.extraVeths.<name>` and not configuring one of `containers.<name>.localAddress`, `.localAddress6`, `.hostAddress`, `.hostAddress6` or `.hostBridge` the veth was created, but otherwise no configuration (i.e. no ip) was applied. nixos-container always configures the primary veth (when `.localAddress` or `.hostAddress` is set) to be the containers default gateway, so this fix is required to create a veth in containers that use a different default gateway. To test this patch configure the following container and check if the addresses are applied: ``` containers.testveth = { extraVeths.testveth = { hostAddress = "192.168.13.2"; localAddress = "192.168.13.1"; }; config = {...}:{}; }; ```