There seems to be one change[1] which breaks our tests, the route Dst field
is no longer nil for a default route but rather the empty ipnet, i.e.
0.0.0.0/0 and ::/0 so fix that up in our code.
[1] https://github.com/vishvananda/netlink/pull/852
Signed-off-by: Paul Holzinger <pholzing@redhat.com>
