delete minor unreachable code caused by t.Fatalf

[Abirdcfly]

Signed-off-by: Abirdcfly [email protected]

Warning
libnetwork was moved to https://github.com/moby/moby/tree/master/libnetwork

libnetwork has been merged to the main repo of Moby since Docker 22.06.

The old libnetwork repo (https://github.com/moby/libnetwork) now only accepts PR for Docker 20.10,
and will be archived after the EOL of Docker 20.10.

[thaJeztah]

close/reopen to see if that triggers CI (didn't start for some reason)