Code review comment for ~paelzer/ubuntu/+source/open-iscsi:lp-1919461-test-python3-compat

I would not have bothered with keeping python2 compat, and simply did python3-only. Even to the point of SRUing python3 autopkgtest back.

I.e. no fallbacks to old python api, no imports from __future__.

But I guess it does help with testing to ensure that 2&3 still work on i.e. focal.