loongson/pypi: links for python-placeholder

loongson/mirror python-placeholder-0.2.tar.gz
loongson/mirror python-placeholder-0.1.3.tar.gz
loongson/mirror python-placeholder-0.1.2.tar.gz
loongson/mirror python-placeholder-0.1.1.tar.gz
loongson/mirror python-placeholder-0.1.tar.gz