Horizontal scrollbar in TWIM room with RHS collapsed on narrow monitor

[turt2live]

Description

This is a regression of sorts because it's never done this before.

Monitor resolution: 1200x1920

Version information

• Platform: web (in-browser)
• Browser: Chrome 65
• OS: Windows 10
• URL: riot.im/develop

[turt2live]

The scrollbar went away and I scrolled all the way up to the room's conception without getting it back. Closing as 'probably fixed, or not reproducible'.