message: Fix bug on NMS converter
diff: @@ -3643,16 +3643,10 @@ tensorflow::Status ConvertCombinedNMS(OpConverterParams* params) {
  return tensorflow::errors::InvalidArgument(
  "Six inputs expected for CombinedNonMaxSuppression, at ", node_def.name());
  }
  - if (!(inputs.at(0).is_tensor())) {
  - "CombinedNonMaxSuppression expects tensor for boxes, at ", node_def.name();
  - }
  - if (!(inputs.at(1).is_tensor())) {
  - "CombinedNonMaxSuppression expects tensor for scores, at ", node_def.name();
  + if (!(inputs.at(0).is_tensor()) || (inputs.at(1).is_tensor())) {
  + return tensorflow::errors::Unimplemented(
  + "CombinedNonMaxSuppression expects tensor for boxes and scores, at ", node_def.name());
  }
  -// if (!(inputs.at(0).is_tensor()) || (inputs.at(1).is_tensor())) {
  -// return tensorflow::errors::Unimplemented(
  -// "CombinedNonMaxSuppression expects tensor for boxes and scores, at ", node_def.name());
  -// }
  if (!(inputs.at(2).is_weights()) || !(inputs.at(3).is_weights()) ||
  (!inputs.at(4).is_weights()) || !(inputs.at(5).is_weights())) {
  return tensorflow::errors::InvalidArgument(
  