eliminate HKDF when hashing paytos

contrib/gana

@@ -1 +1 @@
-Subproject commit 17555514bd2866e0d45b23e4a1c198415205c8f2
+Subproject commit 8c7d9be40ba627348da3e01b91b4f1d3cc78631f

src/util/payto.c

@@ -260,22 +260,7 @@ void
 TALER_payto_hash (const char *payto,
                   struct TALER_PaytoHash *h_payto)
 {
-  /* FIXME: 0.8 had TWO WAYS to hash a payto!
-     one for the exchange, the other
-     for merchants (i.e. reserve closing).
-     I think we should unify... */
-#if OLD_EXCHANGE_WAY
-  GNUNET_assert (GNUNET_YES ==
-                 GNUNET_CRYPTO_kdf (hc,
-                                    sizeof (*hc),
-                                    payto_uri,
-                                    strlen (payto_uri) + 1,
-                                    "exchange-wire-signature",
-                                    strlen ("exchange-wire-signature"),
-                                    NULL, 0));
-#else
   GNUNET_CRYPTO_hash (payto,
                       strlen (payto) + 1,
                       &h_payto->hash);
-#endif
 }