With tabs in a sidebar, multiple displays and Firefox to the left: the scope may appear in the display to the right

## Example

![2017-08-06 08 04 27 tab scope](https://user-images.githubusercontent.com/192271/29005910-bdc64e78-7add-11e7-86a1-03c8195ebc77.png)

## Environment

Firefox 54.0.1 (64-bit)

FreeBSD-CURRENT

[Vertical Tabs Reloaded](https://addons.mozilla.org/firefox/addon/vertical-tabs-reloaded/) 0.8.4-alpha and numerous other extensions

## Workaround

Align on top. 