Remove '&' in OSD messages

Causes weird problems with previous text getting stuck.

src/osd/osdbase.h

@@ -63,6 +63,8 @@ class OSDBase : public QObject {
   virtual bool SupportsNativeNotifications();
   virtual bool SupportsTrayPopups();
 
+  QString app_name() { return app_name_; }
+
  public slots:
   void ReloadSettings();