[SceneCreator] FIX build error with AppleClang 6.0.0.6000051
[SceneCreator] FIX build error with AppleClang 6.0.0.6000051

error: chosen constructor is explicit in copy-initialization

FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa,FabienPean/sofa