cherry-pick of "Merge branch '21.6-Powheg_MadSpin_ErrorLog_Fix' into '21.6'"
PowhegControl: bugfix in MadSpin log messages which was triggering an error by mistake - AGENE-2086
See merge request !47414 (merged)
(cherry picked from commit 85971c5d)
1d84315f PowhegControl: bugfix in MadSpin log messages which was triggering an error by mistake - AGENE-2086