Fix adaptive layer when slicing tolerance is middle
Fix adaptive layer when slicing tolerance is middle

CURA-4813

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