Add option "Activate gestures on right mouse click only when a modifier is holding down (Ctrl/Shift/Alt/combinations: Ctrl+Shift/etc..)"

[helperman]

I want to activate gesture only when Ctrl-button on keyboard is held down.
The certain modifier key should be customizable in options (someone wants Ctrl, someone wants Alt + Shift)

Test case:
if Ctrl button is held down than the gesture is activated.
if Ctrl button is not held down than the gesture is not activated.

[Robbendebiene]

Hi thanks for the suggestion.
This has already been requested.

So I'm closing this as a duplicate of #274

[helperman]

Oops, sorry. I described a feature incorrectly. I want to activate a gesture with right mouse click only if a specified modifier is holding down.