loongson/pypi: links for pg-xmlsig

loongson/mirror pg-xmlsig-0.0.3.tar.gz
loongson/mirror pg_xmlsig-0.0.3-py2.py3-none-any.whl
loongson/mirror pg-xmlsig-0.0.2.tar.gz
loongson/mirror pg_xmlsig-0.0.2-py2.py3-none-any.whl
loongson/mirror pg-xmlsig-0.0.1.tar.gz
loongson/mirror pg_xmlsig-0.0.1-py2.py3-none-any.whl