loongson/pypi: links for extcmd

loongson/mirror extcmd-1.1.tar.gz
loongson/mirror extcmd-1.0.1.tar.gz
loongson/mirror extcmd-1.0.tar.gz
loongson/mirror extcmd-1.0b4.tar.gz
loongson/mirror extcmd-1.0b2.tar.gz
loongson/mirror extcmd-1.0b1.tar.gz
loongson/mirror extcmd-0.1.dev2.tar.gz
loongson/mirror extcmd-0.1.dev1.tar.gz