ignore-scrolling + jitter unhides cursor on first scrolling

[astier]

unclutter-xfixes version: 1.5

Problem

unclutter --ignore-scrolling --jitter 1 unhides the cursor on the very first scrolling. After that unclutter ignores scrolling and keeps the cursor hidden as expected.

Reproduce

1. Execute unclutter --ignore-scrolling --jitter 1
2. DO NOT move the mouse and wait until the cursor is hidden
3. Scroll without moving the mouse
4. See that the mouse is visible now
5. Wait again until the mouse is hidden
6. Scroll again without moving the mouse and see that the mouse is now hidden as expected