For master devices, instead of ignoring loss of carrier entirely,
handle it.
First of all, master devices are now by default ignore-carrier=yes.
That means, without explict user configuration in NetworkManager.conf,
the previous behavior in carrier_changed() does not change.
If the user decides to configure the master device like
[device-with-carrier]
match-device=type:bond,type:bridge,type:team
ignore-carrier=no
then, master device will disconnect on carrier loss like
regular devices.
https://github.com/NetworkManager/NetworkManager/pull/18
Co-authored-by: Thomas Haller <thaller@redhat.com>