Unmount USB drive with names containing spaces

Hi there.

It should be easy to fix. My USB key contains a space character, “OCZ Diesel”, when I try to unmount it, it fails, the command line does not handle space in the mount point:

Capture d’écran 2021-04-02 055325

First line is in French, but the next lines are explicits.

It should work better with quotes …

Volumio Version: 2.873
Hardware: RPi 4