prevent (or support) slicing for 3D crystals
Replace code
if (iff && re_layout.numberOfSlices() > 1 && !iff->supportsMultilayer())
throw std::runtime_error("LayoutStrategyBuilder::checkInterference: "
"interference function does not support multiple layers");
that has been removed in 6bb163ab "ProcessedLayouts: rm m_n_slices"