UI: Use main video on the virtual camera if program

This change allows the virtual camera to really output what is in the
program view, some plugin interract with this view but their changes
does not appear on the virtual camera.

UI/window-basic-main.hpp

@@ -656,6 +656,8 @@ private:
 
 	void UpdatePreviewOverflowSettings();
 
+	bool restartingVCam = false;
+
 public slots:
 	void DeferSaveBegin();
 	void DeferSaveEnd();
@@ -830,6 +832,8 @@ private slots:
 	void ResetProxyStyleSliders();
 
 	void UpdateVirtualCamConfig(const VCamConfig &config);
+	void RestartVirtualCam(const VCamConfig &config);
+	void RestartingVirtualCam();
 
 private:
 	/* OBS Callbacks */