`extended_to_public` panics on a random extended_secret

[satoshiotomakan]

How to reproduce:

let extended_secret = [185, 89, 238, 245, 153, 149, 65, 7, 75, 142, 69, 123, 161, 216, 98, 76, 42, 1, 156, 2, 43, 18, 165, 125, 198, 124, 60, 211, 163, 33, 197, 226, 47, 48, 158, 138, 96, 245, 241, 239, 69, 72, 135, 32, 163, 121, 200, 72, 132, 19, 69, 49, 72, 155, 56, 25, 90, 91, 162, 174, 169, 17, 158, 157];

let msg = any_msg();
cryptoxide::ed25519::signature_extended(&msg, &extended_secret);

assertion failed: b >= -8 && b <= 8
thread 'test_ed25519_extended_cardano_sign' panicked at 'assertion failed: b >= -8 && b <= 8', src/index.crates.io-6f17d22bba15001f/cryptoxide-0.4.4/src/curve25519/ge.rs:509:9
stack backtrace:

[satoshiotomakan]

I expect from cryptoxide::ed25519::signature_extended to return an error in case if the extended secret is invalid.