Re-enable skirt if draft shield disabled but height is not 0
Re-enable skirt if draft shield disabled but height is not 0

It used to only look at the height.

Contributes to issue CURA-1295.

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