loongson/pypi: links for bootstrap4

loongson/mirror bootstrap4-0.1.0.tar.gz
loongson/mirror bootstrap4-0.0.5.tar.gz
loongson/mirror bootstrap4-0.0.4.tar.gz
loongson/mirror bootstrap4-0.0.3.tar.gz
loongson/mirror bootstrap4-0.0.2.tar.gz
loongson/mirror bootstrap4-0.0.1.tar.gz