Fix crash with PPP interface with nil dst address

balenaEngine initialization would fail on devices connected to the
network via PPP (Point-to-Point Protocol) and with a nil destination
address (0.0.0.0):

    panic: runtime error: invalid memory address or nil pointer dereference

This commit updates the netlink dependency to a fork where we
cherry-picked the correction. This correction wasn't available in any
stable release of netlink, so we opted to use this fork instead of
relying on a beta netlink version. We can obsolete our fork once Moby
starts using a netlink version that includes the fix.

Fixes #292

Signed-off-by: Leandro Motta Barros <leandro@balena.io>
Change-type: patch

vendor.conf

@@ -60,7 +60,7 @@ github.com/hashicorp/go-multierror                  886a7fbe3eb1c874d46f623bfa70
 github.com/hashicorp/serf                           598c54895cc5a7b1a24a398d635e8c0ea0959870
 github.com/docker/libkv                             458977154600b9f23984d9f4b82e79570b5ae12b
 github.com/vishvananda/netns                        db3c7e526aae966c4ccfa6c8189b693d6ac5d202
-github.com/vishvananda/netlink                      f049be6f391489d3f374498fe0c8df8449258372 # v1.1.0
+github.com/vishvananda/netlink                      6236117f04b0e3512d396660b61d5b1e47a01606 https://github.com/balena-os/balena-netlink # v1.1.0 + "Correct panic when IPv4 lacks IFA_ADDRESS address"
 github.com/moby/ipvs                                4566ccea0e08d68e9614c3e7a64a23b850c4bb35 # v1.0.1
 
 # When updating, consider updating TOMLV_COMMIT in hack/dockerfile/install/tomlv.installer accordingly