loongson/pypi: links for l1l2signature

loongson/mirror L1L2Signature-0.2.4.tar.gz
loongson/mirror L1L2Signature-0.2.2.tar.gz
loongson/mirror L1L2Signature-0.2.1.tar.gz
loongson/mirror L1L2Signature-0.2.0.tar.gz