Description of the new feature/enhancement

a switch or configurable key for disable/enable <ctrl> + "mouse middle button scroll" to scale font size;

i searched through the doc but find no way to disable this action. sometimes this is really annoying on laptop with a touchpad. The ctrl key pressing state seems to keep a little longer after 'keyup', or i may just act too quick. When scroll on touchpad with two fingers after a <ctrl + "any key"> shortcut, it always miss behaving like to scale text when i mean to scroll the screen

Proposed technical implementation details (optional)