re-enable zero fee check

Author: Tom Trevethan

src/confidential_validation.cpp

@@ -30,7 +30,7 @@ bool HasValidFee(const CTransaction& tx) {
         CAmount fee = 0;
         if (tx.vout[i].IsFee()) {
             fee = tx.vout[i].nValue.GetAmount();
-            if (!MoneyRange(fee)) {
+            if (fee == 0 || !MoneyRange(fee)) {
                 return false;
             }
             totalFee[tx.vout[i].nAsset.GetAsset()] += fee;

src/wallet/spend.cpp

@@ -1451,10 +1451,6 @@ static bool CreateTransactionInternal(
         txNew = tx_blinded; // sigh, `fillBlindDetails` may have modified txNew
         // Update the change position to the new tx
         change_position = txNew.vout.begin() + nChangePosInOut;
-<<<<<<< HEAD
-=======
-
->>>>>>> origin/master
         int ret = BlindTransaction(blind_details->i_amount_blinds, blind_details->i_asset_blinds, blind_details->i_assets, blind_details->i_amounts, blind_details->o_amount_blinds, blind_details->o_asset_blinds, blind_details->o_pubkeys, issuance_asset_keys, issuance_token_keys, tx_blinded);
         assert(ret != -1);
         if (ret != blind_details->num_to_blind) {