package/network-manager: drop --disable-ifnet
ifnet has been drop since version 1.12.0 and
https://github.com/NetworkManager/NetworkManager/commit/0474441e2258eeecb356e2aa3cde5c7328828646
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>