message: Fix random crash when opening 'Insert DNA/RNA' dialog
diff: @@ -40,7 +40,7 @@ namespace QtPlugins {
  InsertDna::InsertDna(QObject* parent_)
  : Avogadro::QtGui::ExtensionPlugin(parent_), m_reader(nullptr),
  - m_molecule(nullptr)
  + m_molecule(nullptr), m_dialog(nullptr)
  {
  QAction* action = new QAction(tr("DNA/RNA..."), this);
  connect(action, SIGNAL(triggered()), SLOT(showDialog()));
  