message: qt, rpc: Accept stop RPC even another command is executing
  While here, clean up the command input by calling the trimmed function
  on the input from the command prompt.
diff: @@ -930,7 +930,7 @@ void RPCConsole::setMempoolSize(long numberOfTxs, size_t dynUsage)
  void RPCConsole::on_lineEdit_returnPressed()
  {
  - QString cmd = ui->lineEdit->text();
  + QString cmd = ui->lineEdit->text().trimmed();
  if (cmd.isEmpty()) {
  return;
  @@ -948,6 +948,13 @@ void RPCConsole::on_lineEdit_returnPressed()
  return;
  }
  + // A special case allows to request shutdown even a long-running command is executed.
  + if (cmd == QLatin1String("stop")) {
  + std::string dummy;
  + RPCExecuteCommandLine(m_node, dummy, cmd.toStdString());
  + return;
  + }
  +
  ui->lineEdit->clear();
  #ifdef ENABLE_WALLET
  