loongson/pypi: links for vissim2gmns

loongson/mirror vissim2gmns-1.5.6.tar.gz
loongson/mirror vissim2gmns-1.5.6-py3-none-any.whl
loongson/mirror vissim2gmns-1.5.5.tar.gz
loongson/mirror vissim2gmns-1.5.5-py3-none-any.whl
loongson/mirror vissim2gmns-1.5.4a1.tar.gz
loongson/mirror vissim2gmns-1.5.4a1-py3-none-any.whl