message: [GUI] Add more explicative message for "Transaction too large"
diff: @@ -527,7 +527,11 @@ WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransact
  if ((total + nFeeRequired) > nBalance) {
  return SendCoinsReturn(AmountWithFeeExceedsBalance);
  }
  - Q_EMIT message(tr("Send Coins"), tr("Transaction creation failed!\n%1").arg(QString::fromStdString(strFailReason)),
  +
  + Q_EMIT message(tr("Send Coins"), tr("Transaction creation failed!\n%1").arg(
  + strFailReason == "Transaction too large" ?
  + tr("The size of the transaction is too big.\nSelect fewer inputs with coin control.") :
  + QString::fromStdString(strFailReason)),
  CClientUIInterface::MSG_ERROR);
  return TransactionCreationFailed;
  }
  