message: Fix crash: CoinControl "space" bug
  This is a port of the pull made by fsb4000 for Bitcoin Core to fix the crash problem: CoinControl "space" bug.
diff: @@ -13,6 +13,7 @@ void CoinControlTreeWidget::keyPressEvent(QKeyEvent *event)
  {
  event->ignore();
  int COLUMN_CHECKBOX = 0;
  + if(this->currentItem())
  this->currentItem()->setCheckState(COLUMN_CHECKBOX, ((this->currentItem()->checkState(COLUMN_CHECKBOX) == Qt::Checked) ? Qt::Unchecked : Qt::Checked));
  }
  else if (event->key() == Qt::Key_Escape) // press esc -> close dialog
  