In addConnectingTravelMove() also force a retraction if retract_at_layer_change is true.
In addConnectingTravelMove() also force a retraction if retract_at_layer_change is true.

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