Upon opening the Shortcut Manager window, no category is highlighted.

1. Install Unity
2. Open Unity
3. Create a new project with any settings
4. When the project is created, go to Edit > Shortcuts
5. Look at the Category list

Expected Result:
The currently selected category should be highlighted.

Actual Result:
No category is highlighted.

Tested on Windows.

Occurs on:
2019.1.0a12

Does not occur on:
2019.1.0a11