loongson/pypi: links for saturn-proxy-server

loongson/mirror saturn_proxy_server-0.9.tar.gz
loongson/mirror saturn_proxy_server-0.7.tar.gz
loongson/mirror saturn_proxy_server-0.6.tar.gz
loongson/mirror saturn_proxy_server-0.5.tar.gz
loongson/mirror saturn_proxy_server-0.4.tar.gz