Erase changed hotends/materials after applying changes
Erase changed hotends/materials after applying changes

Otherwise we may only change one of the extruders next time, and it'll still have the other change in this dictionary from the previous time we are syncing from the printer.

Contributes to issue CURA-3788.

fieldOfView/Cura,ynotstartups/Wanhao,fieldOfView/Cura,ynotstartups/Wanhao,Curahelper/Cura,Curahelper/Cura