Comment 2 for bug 2031845

On Mantic 6.5.0-1, this test is failing with "Error: Unsupported attribute." as well:
 Running './ubuntu_fan_smoke_test.sh 172.17.0.0/16'
 Testing Fan Networking (pre-0.13.0 API)
 docker pull --platform linux/amd64 ubuntu: PASSED
 Error: Unsupported attribute.
 /usr/sbin/fanctl: ip link add ftun0 type vxlan id 16384000 dev docker0 dstport 0 local 172.17.0.1 fan-map 250.0.0.0/8:172.17.0.0/16
 /usr/sbin/fanctl: WARNING: ftun0: failed to configure address translation
 RTNETLINK answers: Cannot assign requested address
 iptables v1.8.7 (nf_tables): Chain 'fan-egress' does not exist
 Try `iptables -h' or 'iptables --help' for more information.
 iptables: Bad rule (does a matching rule exist in that chain?).
 iptables: Bad rule (does a matching rule exist in that chain?).
 iptables: No chain/target/match by that name.
 rm: cannot remove '/run/ubuntu-fan/nat-core': No such file or directory
 /usr/sbin/fanatic: unable to bring fan up, unable to configure
 enable disable fan test: FAILED (fanatic enable-fan returned 1)