GPL: Replace contribution from Lucian

We need to replace the contribution, because Lucian is not responding,
and thus preventing us to use the new license on his code [0].

See the chain leading to [1] on how this reverts
his contribution, and adds a new fix.
Unfortunately we cannot merge that chain one-by-one,
because Python version is different now,
so verify fails for intermediate changes.

This is the chain squashed into the single change,
so it can be verified and merged.

[0] https://gerrit.fd.io/r/c/csit/+/11530
[1] https://gerrit.fd.io/r/c/csit/+/29481/2

Change-Id: I00ab3786e1d9abc28fed778b36d814d293c49383
Signed-off-by: Vratko Polak <vrpolak@cisco.com>