python/crypto/keepass_decode: add Ubuntu 20.04 support
python/crypto/keepass_decode: add Ubuntu 20.04 support

On Ubuntu 20.04, python3-pycryptodome installs PyCryptodome in
namespace Cryptodome, not Crypto.

fishilico/shared,fishilico/shared,fishilico/shared,fishilico/shared,fishilico/shared,fishilico/shared,fishilico/shared