[music] Fix bug in generating log data form

vrobbler/apps/scrobbles/views.py

@@ -940,7 +940,7 @@ class ScrobbleDetailView(DetailView):
     slug_url_kwarg = "uuid"
 
     def get_form_class(self):
-        return self.object.media_obj.logdata_cls.form()
+        return self.object.media_obj.logdata_cls().form()
 
     def get_form(self):
         FormClass = self.get_form_class()