Correct error message for prd signed by ourselves

src/prd.rs

@@ -161,7 +161,7 @@ impl Prd {
             let local_spend_key: XOnlyPublicKey = local_address.get_spend_key().x_only_public_key().0;
             // If it's our own device key we abort
             if proof_key == local_spend_key {
-                return Err(anyhow::Error::msg("Proof signed with an unknown key"));
+                return Err(anyhow::Error::msg("Proof signed by ourselves, we are parsing our own message"));
             }
             // take the spending keys in sender
             let sender: Member = serde_json::from_str(&prd.sender)?;