Unlike osmo-ggsn, open5gs-upfd does not configure the tun interface
itself. All IPv4/IPv6 addresses must be assigned manually. This
is exactly why both PGW_Tests.TC_createSession_ping4[_256] fail:
[sock] ERROR: ogs_write() failed (5:Input/outputerror) (../lib/tun/tunio.c:84)
[upf] WARNING: ogs_tun_write() failed (../src/upf/gtp-path.c:448)
Take Harald's setup.sh from open5gs-master and execute it in the
container running open5gs-upfd. This fixes the ogs_write() errors.
Change-Id: I0730b1f69285484a0aa0ebd664dafd8e476b294f
Related: SYS#5602
