adjust documentation: secp256k1_ec_seckey_verify

include/secp256k1.h

@@ -679,12 +679,14 @@ SECP256K1_API int secp256k1_ecdsa_sign(
  const void *ndata
 ) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
 
-/** Verify an ECDSA secret key.
+/** Verify an elliptic curve secret key.
  *
  * A secret key is valid if it is not 0 and less than the secp256k1 curve order
  * when interpreted as an integer (most significant byte first). The
  * probability of choosing a 32-byte string uniformly at random which is an
- * invalid secret key is negligible.
+ * invalid secret key is negligible. However, if it does happen it should 
+ * be assumed that the randomness source is severely broken and there should
+ * be no retry.
  *
  * Returns: 1: secret key is valid
  * 0: secret key is invalid