CTRL+touchpad zoom sensitivity is too high

[lineinthesand]

When I attempt zooming via CTRL+touchpad (i.e. CTRL+two-finger-movement) this is almost impossible to control as tiiny, tiny movements have to be made to achieve the desired zoom level.

I prepared a patch where I fixed this problem by introducing a scroll delta that has to be overcome in order to trigger a zoom event. I've submitted a similar patch to kdenlive in the past where it was merged (see sandsmark/kdenlive@b7f5e7c).

I'll create a pull request for this issue.

Edit: I just saw that this apparently fixed in the master branch for qt6; I had that problem with 1.6.2, qt5. Could this still be included in 1.6.3 (1.6.4)?