loongson/pypi: links for six

INFO: Because this project isn't in the mirror_whitelist, no releases from root/pypi are included.

loongson/pypi six-1.16.0-py2.py3-none-any.whl
loongson/pypi six-1.15.0-py2.py3-none-any.whl
loongson/pypi six-1.12.0-py2.py3-none-any.whl
loongson/pypi six-1.11.0-py2.py3-none-any.whl