Fix prefjson::setPreferences() doesn't actually save.

src/app/application.h

@@ -30,6 +30,7 @@
 #ifndef APPLICATION_H
 #define APPLICATION_H
 
+#include <QPointer>
 #include <QStringList>
 #include <QTranslator>
 
@@ -42,6 +43,10 @@ class MainWindow;
 typedef QtSingleCoreApplication BaseApplication;
 #endif
 
+#ifndef DISABLE_WEBUI
+class WebUI;
+#endif
+
 class Application : public BaseApplication
 {
     Q_OBJECT
@@ -69,9 +74,15 @@ private slots:
 
 private:
     bool m_running;
+
 #ifndef DISABLE_GUI
     QPointer<MainWindow> m_window;
 #endif
+
+#ifndef DISABLE_WEBUI
+    QPointer<WebUI> m_webui;
+#endif
+
     QTranslator m_qtTranslator;
     QTranslator m_translator;
     QStringList m_paramsQueue;