In previous releases all these methods were a no-op if the network
driver is disabled. These helper methods are called unconditionally for
all types of network interface, so must be no-ops if missing. Other code
will already generate an error if the network driver is disabled and a
NIC with type=network is used.
Reviewed-by: NLaine Stump <laine@laine.org>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>