Fix memory leak.

src/gui/shutdownconfirm.cpp

@@ -74,6 +74,11 @@ ShutdownConfirmDlg::ShutdownConfirmDlg(const ShutdownAction &action)
     move(Utils::Misc::screenCenter(this));
 }
 
+ShutdownConfirmDlg::~ShutdownConfirmDlg()
+{
+  delete ui;
+}
+
 void ShutdownConfirmDlg::showEvent(QShowEvent *event)
 {
     QDialog::showEvent(event);

src/gui/shutdownconfirm.h

@@ -49,6 +49,7 @@ class ShutdownConfirmDlg : public QDialog
 
 public:
     ShutdownConfirmDlg(const ShutdownAction &action);
+    ~ShutdownConfirmDlg();
     bool shutdown() const;
 
     static bool askForConfirmation(const ShutdownAction &action);