fix: don't generate perimeter_gaps between inner wall and infill/skin when there is no infill (CURA-3108)
fix: don't generate perimeter_gaps between inner wall and infill/skin when there is no infill (CURA-3108)

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