loongson/pypi: links for btcsignature

loongson/mirror btcsignature-0.13.4.tar.gz
loongson/mirror btcsignature-0.13.3.tar.gz
loongson/mirror btcsignature-0.13.2.tar.gz
loongson/mirror btcsignature-0.13.1.tar.gz
loongson/mirror btcsignature-0.13.tar.gz
loongson/mirror btcsignature-0.12.tar.gz
loongson/mirror btcsignature-0.11.tar.gz
loongson/mirror btcsignature-0.1.tar.gz