Work around debug being loaded in preload scripts

[anaisbetts]

This is a follow-on to #324, where if debug is loaded in a preload script (https://github.com/electron/electron/blob/d6e3360aeff6c50820a08af28f1097a0c25d6e3e/docs/api/web-view-tag.md#preload), it will crash in useColors because the DOM is not fully set-up yet (window.document.documentElement will be undefined, but window.document exists)

[thebigredgeek]

#369 < wondering if this is the same issue?

[anaisbetts]

@thebigredgeek Doesn't look like it but might be related? The callstack for us was trying to access style of null (aka document not null, but document.documentElement is null)

[anaisbetts]

@thebigredgeek If you could cut a release off of this we'd be v grateful, this debug issue is causing us a lot of grief over at Slack because we use it in lots of low-level components that aren't easily patched

[thebigredgeek]

@paulcbetts done :). 2.4.4 now live

[anaisbetts]

Thank you so much!

[thebigredgeek]

Np! Good luck