Cameras.gltf provoke VTK warning

Opening Camera.gltf causes a VTK warning:

Warning: In /home/glow/work/vtk/vtk1/src/IO/Geometry/vtkGLTFDocumentLoaderInternals.cxx, line 872
vtkGLTFDocumentLoader (0x5614ea525920): Invalid node.rotation value. Using normalized rotation for node