HowTo make vert scroll default mousewheel action, not zoom?

When I'm editing a midi track I want the default mousewheel action to be vertical scroll (the default assignment of ctrl-alt-mousewheel) instead of horizontal zoom. There is no option in the perferences dialog, so I assume it's in some .ini file. Can someone point (& click) the way for me? TIA!

Nevermind, I found the manual, downloaded it and found the answer.

Main menu Actions->Show action list... Change shortcuts. Click on Add to assign the mousewheel or kc.