Update UPGRADE.md
Update UPGRADE.md

Fix for the Mopidy logging to provide SDcard flooding.
MiczFlor/RPi-Jukebox-RFID,MiczFlor/RPi-Jukebox-RFID,MiczFlor/RPi-Jukebox-RFID,MiczFlor/RPi-Jukebox-RFID,MiczFlor/RPi-Jukebox-RFID