Fix ExtruderManager.py
Fix ExtruderManager.py

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