Fix crash on exiting GUI

Source/AccessClass.cpp

@@ -57,6 +57,11 @@ namespace AccessClass
 			bc->addActionListener(mc);
 		}
 
+		void shutdownBroadcaster()
+		{
+			bc = nullptr;
+		}
+
 		/** Returns a pointer to the application's EditorViewport. */
 		EditorViewport* getEditorViewport()
 		{

Source/AccessClass.h

@@ -47,6 +47,8 @@ namespace AccessClass
 			*/
 		void setUIComponent(UIComponent*);
 
+		void shutdownBroadcaster();
+
 
 		/** Returns a pointer to the application's EditorViewport. */
 		EditorViewport* getEditorViewport();

Source/UI/UIComponent.cpp

@@ -91,6 +91,7 @@ UIComponent::UIComponent(MainWindow* mainWindow_, ProcessorGraph* pgraph, AudioC
 UIComponent::~UIComponent()
 {
     dataViewport->destroyTab(0); // get rid of tab for InfoLabel
+	AccessClass::shutdownBroadcaster();
 }
 
 void UIComponent::resized()