loongson/pypi: links for json2struct

loongson/mirror json2struct-1.4.1.tar.gz
loongson/mirror json2struct-1.2.tar.gz
loongson/mirror json2struct-1.1.tar.gz
loongson/mirror json2struct-1.0.tar.gz
loongson/mirror json2struct-0.999.tar.gz