Cardboard VR remove the need for alt key on mouse up/down

Could anyone please tell me how to remove having to press alt-mouse up/down in unity google cardboard VR when testing on the PC ? I need my PC test VR app just to use the mouse in the regular FPS way. The mouse works fine for left and right but up down is mapped to pressing the alt-up/down key

in EditorDevice.cs:

if (Input.GetKey(KeyCode.LeftAlt) || Input.GetKey(KeyCode.RightAlt))

comment this out.