Use RepeatedPtrField::Get instead of RepeatedPtrField::operator[], to be compatible with protobuf 3.0 API (#4354)
Use RepeatedPtrField::Get instead of RepeatedPtrField::operator[], to be compatible with protobuf 3.0 API (#4354)

Signed-off-by: Joaquin Anton <7bc6c671a726e7dca78d9173c4d1c96eb5595db1@nvidia.com>

Co-authored-by: Chun-Wei Chen <3d21e1cad9aa0e4aa10838f859be24690cfc357c@gmail.com>
onnx/onnx,onnx/onnx,onnx/onnx,onnx/onnx