Highlight of active repository in filepicker misaligned

Discovered on qa.moodle.net: In the filepicker dialog, the currently active repository is highlighted. The highlight does not align well with the rest (cf. screenshot below). 

Steps to reproduce

1. go to https://qa.moodle.net, log in as teacher/test.
2. go into a course, e.g. 101 and turn editing on.
3. start adding a File resource to the course.
4. under Select files, click Add ....
5. on the left, the active repository is highlighted as in the screenshot.