loongson/pypi: links for noticeslackline

loongson/mirror NoticeSlackLine-0.2.1b2.tar.gz
loongson/mirror NoticeSlackLine-0.2.1b2-py3-none-any.whl
loongson/mirror NoticeSlackLine-0.2.1b1-py3-none-any.whl
loongson/mirror NoticeSlackLine-0.2.1b0-py3-none-any.whl