loongson/pypi: links for steampy-proxy

loongson/mirror steampy-proxy-0.78.tar.gz
loongson/mirror steampy-proxy-0.77.tar.gz
loongson/mirror steampy-proxy-0.76.tar.gz
loongson/mirror steampy-proxy-0.75.tar.gz
loongson/mirror steampy-proxy-0.74.tar.gz