message: gltfpack: Cleanup mimeType flow a bit
  We now always use mimeType from JSON if present as instructed by glTF
  specification; this makes the code slightly cleaner as well.
diff: @@ -549,14 +549,15 @@ void writeImage(std::string& json, std::vector<BufferView>& views, const cgltf_i
  {
  // we will re-embed img_data below
  }
  - else if (image.buffer_view && image.buffer_view->buffer->data && image.mime_type)
  + else if (image.buffer_view && image.buffer_view->buffer->data)
  {
  const cgltf_buffer_view* view = image.buffer_view;
  img_data.assign(static_cast<const char*>(view->buffer->data) + view->offset, view->size);
  - mime_type = image.mime_type;
  }
  - else if (image.uri && settings.texture_embed)
  + else if (image.uri)
  + {
  + if (settings.texture_embed)
  {
  std::string full_path = getFullPath(image.uri, input_path);
  @@ -564,13 +565,13 @@ void writeImage(std::string& json, std::vector<BufferView>& views, const cgltf_i
  {
  fprintf(stderr, "Warning: unable to read image %s, skipping\n", image.uri);
  }
  + }
  mime_type = inferMimeType(image.uri);
  }
  - else if (image.uri)
  - {
  - mime_type = image.mime_type ? image.mime_type : inferMimeType(image.uri);
  - }
  +
  + if (image.mime_type)
  + mime_type = image.mime_type;
  if (!img_data.empty())
  {
  