safety: more asserts in LayerPlanBuffer::addConnectingTravelMove (CURA-3553)
safety: more asserts in LayerPlanBuffer::addConnectingTravelMove (CURA-3553)

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