Fix ambiguous StandaloneWindow::getApp()

Signed-off-by: falkTX <falktx@falktx.com>

dgl/StandaloneWindow.hpp

@@ -71,6 +71,7 @@ public:
     bool addIdleCallback(IdleCallback* callback, uint timerFrequencyInMs = 0)
     { return Window::addIdleCallback(callback, timerFrequencyInMs); }
     bool removeIdleCallback(IdleCallback* callback) { return Window::removeIdleCallback(callback); }
+    Application& getApp() const noexcept { return Window::getApp(); }
     const GraphicsContext& getGraphicsContext() const noexcept { return Window::getGraphicsContext(); }
     double getScaleFactor() const noexcept { return Window::getScaleFactor(); }
     void setGeometryConstraints(uint minimumWidth, uint minimumHeight,