fix: heat to print temp if prev extruder plan was empty (CURA-3537)
fix: heat to print temp if prev extruder plan was empty (CURA-3537)

alephobjects/CuraEngine,ROBO3D/CuraEngine,Ultimaker/CuraEngine,Ultimaker/CuraEngine,alephobjects/CuraEngine,ROBO3D/CuraEngine,alephobjects/CuraEngine,ROBO3D/CuraEngine