Comment 3 for bug 1845909

I'm running Ubuntu 19.04 with systemd 240-6ubuntu5.7

systemd-networkd configuration:
```
# eno1.network
[Match]
Name=eno1

[Link]
Multicast=no

[Network]
LinkLocalAddressing=no
Address=192.168.50.249/24
Gateway=192.168.50.1
DNS=192.168.50.1
VLAN=pppoe

# pppoe.netdev
[NetDev]
Name=pppoe
Kind=vlan

[VLAN]
Id=1006

# pppoe.network
[Match]
Name=pppoe

[Link]
Multicast=no
ARP=no

[Network]
LinkLocalAddressing=no
```

result:
```
# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 94:c6:91:18:8c:3c brd ff:ff:ff:ff:ff:ff
    inet 192.168.50.249/24 brd 192.168.50.255 scope global eno1
       valid_lft forever preferred_lft forever
3: wlp58s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 40:a3:cc:22:45:25 brd ff:ff:ff:ff:ff:ff
4: pppoe@eno1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 94:c6:91:18:8c:3c brd ff:ff:ff:ff:ff:ff
    inet6 fe80::96c6:91ff:fe18:8c3c/64 scope link
       valid_lft forever preferred_lft forever
5: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether 02:42:3c:35:9c:76 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever
```

The pppoe interface still got an IPv6 link-local address.