loongson/pypi: links for pyarithcalc

loongson/mirror pyarithcalc-1.7.tar.gz
loongson/mirror pyarithcalc-1.6.tar.gz
loongson/mirror pyarithcalc-1.5.tar.gz
loongson/mirror pyarithcalc-1.4.tar.gz
loongson/mirror pyarithcalc-1.3.tar.gz
loongson/mirror pyarithcalc-0.7.tar.gz
loongson/mirror pyarithcalc-0.6.tar.gz