core: fix creation of v1 txes

src/cryptonote_core/cryptonote_tx_utils.cpp

@@ -320,6 +320,7 @@ namespace cryptonote
     });
     tools::apply_permutation(outs_order, [&] (size_t i0, size_t i1) {
       std::swap(tx.vout[i0], tx.vout[i1]);
+      if (!amount_keys.empty())
         std::swap(amount_keys[i0], amount_keys[i1]);
     });