loongson/pypi: links for excentury

loongson/mirror excentury-0.2.4.tar.gz
loongson/mirror excentury-0.2.3.tar.gz
loongson/mirror excentury-0.2.2.tar.gz
loongson/mirror excentury-0.2.1.tar.gz
loongson/mirror excentury-0.2.tar.gz
loongson/mirror excentury-0.2b0.tar.gz