Shouldn't show red box when canceling dwell by turning off the dwell clicker

[1j01]

Currently a red rectangle is shown around the border of the screen if you turn the dwell clicker off while a dwell is in progress.
It should simply show the dwell as canceled (ideally with an animation: #12)

The red rectangle represents an occluding element. There's no occluder in this case, but I see I do show_occluder_indicator(occluder || document.body);
Perhaps this is just a stopgap in lieu of a dwell click cancel animation? Or perhaps there's some case I'm not considering. I should take a peek at the git blame before changing this, but it's probably fine.

(The red dotted outline looks almost like it's starting to record the screen or something, when it covers the screen.)