using the pre-existing and well-tested GetExtension() (which happens to also normalize the extension), rather than attempting our own buggy one... Closes: https://github.com/assimp/assimp/issues/4177
using the pre-existing and well-tested GetExtension() (which happens to also normalize the extension), rather than attempting our own buggy one... Closes: https://github.com/assimp/assimp/issues/4177