The maximize button doesn't work for the "Repository Application"

Steps to reproduce:

• Install the Repository Application on your wiki
• Go to the "Extension Repository" homepage and click on "Import"
• Write an extension id in the field and then click "Import"
• Edit that extension inline
• Click on the "maximize" button for the Description or for the "Custom installation instructions" field

You don't have access to the "Exit fullscreen" or the "Save" buttons. You can however save the page by using the shortcut (Alt+S).