loongson/mirror: links for dcmextras

loongson/mirror dcmextras-0.3.5.tar.gz
loongson/mirror dcmextras-0.3.5-py3-none-any.whl
loongson/mirror dcmextras-0.3.4.tar.gz
loongson/mirror dcmextras-0.3.4-py3-none-any.whl