Fix missing use of dustRelayFee

Author: morcos

src/wallet/rpcwallet.cpp

@@ -2834,7 +2834,7 @@ UniValue bumpfee(const JSONRPCRequest& request)
 
     // If the output would become dust, discard it (converting the dust to fee)
     poutput->nValue -= nDelta;
-    if (poutput->nValue <= poutput->GetDustThreshold(::minRelayTxFee)) {
+    if (poutput->nValue <= poutput->GetDustThreshold(::dustRelayFee)) {
         LogPrint("rpc", "Bumping fee and discarding dust output\n");
         nNewFee += poutput->nValue;
         tx.vout.erase(tx.vout.begin() + nOutput);