message: fix for ERROR:Invalid inlined_image_type in cached_result
  Fixes
diff: @@ -2038,10 +2038,7 @@ InlineResult ImageRewriteFilter::TryInline(bool is_html, bool is_critical,
  int64 image_inline_max_bytes, const CachedResult* cached_result,
  ResourceSlot* slot, GoogleString* data_url) {
  int32 image_type_value = cached_result->inlined_image_type();
  - if ((image_type_value < IMAGE_UNKNOWN) ||
  - (image_type_value > IMAGE_WEBP_LOSSLESS_OR_ALPHA)) {
  - // IMAGE_UNKNOWN and IMAGE_WEBP_LOSSLESS_OR_ALPHA must be the smallest
  - // and largest values, respectively, in ImageType enum.
  + if (!ImageType_IsValid(image_type_value)) {
  LOG(DFATAL) << "Invalid inlined_image_type in cached_result";
  return INLINE_INTERNAL_ERROR;
  }
  