JSON fix: default ==> default_value for acceleration and jerk (CURA-1443)
JSON fix: default ==> default_value for acceleration and jerk (CURA-1443)

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