makeSplineApprox cannot throw ValueErrors anymore

[adam-urbanczyk]

It seems that IsDone()==False cannot be reached. See: https://github.com/Open-Cascade-SAS/OCCT/blob/3d097a0328e71b826377d4814ab05ec3c3d23871/src/ModelingAlgorithms/TKGeomAlgo/GeomAPI/GeomAPI_PointsToBSpline.cxx#L115