0 is now seen as a correct value by QualitySettingsModel
0 is now seen as a correct value by QualitySettingsModel

CURA-2293

Curahelper/Cura,ynotstartups/Wanhao,fieldOfView/Cura,totalretribution/Cura,Curahelper/Cura,hmflash/Cura,fieldOfView/Cura,ynotstartups/Wanhao,hmflash/Cura,senttech/Cura,senttech/Cura,totalretribution/Cura