loongson/pypi: links for protobuf-distutils

loongson/mirror protobuf_distutils-1.0.tar.gz
loongson/mirror protobuf_distutils-1.0-py3-none-any.whl
loongson/mirror protobuf_distutils-1.0rc1.tar.gz
loongson/mirror protobuf_distutils-1.0rc1-py3-none-any.whl