[pylint] Pylint 2.10 - unused-variable

Pylint 2.10 fixed [1]:

  Fixed bug with cell-var-from-loop checker: it no longer has false negatives
  when both unused-variable and used-before-assignment are disabled.

[1] https://pylint.pycqa.org/en/latest/whatsnew/2.10.html



Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>