loongson/pypi: links for back-pubg-python

loongson/mirror back-pubg-python-0.5.2.tar.gz
loongson/mirror back_pubg_python-0.5.2-py3-none-any.whl
loongson/mirror back-pubg-python-0.5.1.tar.gz
loongson/mirror back_pubg_python-0.5.1-py3-none-any.whl
loongson/mirror back-pubg-python-0.5.0.tar.gz
loongson/mirror back_pubg_python-0.5.0-py3-none-any.whl