loongson/pypi: links for proxymiddleware

loongson/mirror ProxyMiddleware-1.5.2.tar.gz
loongson/mirror ProxyMiddleware-1.5.1.tar.gz
loongson/mirror ProxyMiddleware-1.4.1.tar.gz
loongson/mirror ProxyMiddleware-1.4.tar.gz
loongson/mirror ProxyMiddleware-1.3.tar.gz
loongson/mirror ProxyMiddleware-1.2.tar.gz