package/netopeer2: bump to version 2.4.1
This is needed following the bump of libyang (3.12.2),
sysrepo (3.6.11) and libnetconf2 (3.7.1), as netopeer2 2.4.1 is the
version designed to work with those other components.
See https://github.com/CESNET/netopeer2/releases for the changes.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>