Dotted outline when clicking on a button/link #1738

Hello,

First of all thank you for this wonderful application !

Describe the bug
I upgraded from 0.26.4 to 0.27.5, and now I have a dotted outline when I click on anything clickable. The outline disappears after the content has loaded

Steps To Reproduce
Steps to reproduce the behavior:

1. Click on any clickable button, for example the logo at the top left
2. When clicking, a dotted outline will appear around the button that's been clicked
3. After the page is loaded, the outline disappears.

Expected behavior
No outline when clicking on anything.

Screenshots

Your Configuration (please complete the following information):

• Exact BookStack Version (Found in settings): 0.27.5
• PHP Version: 7.2
• Hosting Method (Nginx/Apache/Docker): Apache (used pre-made script on Ubuntu 18)

Thanks !