fix cygwin issue

Author: karel-m

src/ltc/pk/ecc/ecc_rfc6979_key.c

@@ -68,7 +68,7 @@ int ecc_rfc6979_key(const ecc_key *priv, const unsigned char *in, unsigned long
                                k, hashsize,
                                k, &klen,
                                v, hashsize,
-                               sep, 1,
+                               sep, (unsigned long)1,
                                buffer, zero_extend,
                                privkey, qlen - zero_extend,
                                buffer, len_diff,
@@ -86,7 +86,7 @@ int ecc_rfc6979_key(const ecc_key *priv, const unsigned char *in, unsigned long
                                k, klen,
                                k, &klen,
                                v, hashsize,
-                               sep, 1,
+                               sep, (unsigned long)1,
                                buffer, zero_extend,
                                privkey, qlen - zero_extend,
                                buffer, len_diff,