Stop Lippupiste importer from updating past events
The importer is importing data for past events daily. This is unnecessary. 

Change the importer so that it does not import past data.
diff --git a/events/importer/lippupiste.py b/events/importer/lippupiste.py
index f7e420c..693949f 100644
--- a/events/importer/lippupiste.py
+++ b/events/importer/lippupiste.py
@@ -458,6 +458,8 @@ class LippupisteImporter(Importer):
         events = super_event.sub_events.filter(deleted=False)
         if not events.exists():
             return
+        # values that should be updated in super-event
+        update_dict = {}
         # name superevent by common part of the subevent names
         names = []
         # only one language existed in feed, therefore we save the common part of *all* names to *all* languages
@@ -473,14 +475,20 @@ class LippupisteImporter(Importer):
             lang = lang[0]
             lang = lang.replace('-', '_')
             if any([getattr(subevent, 'name_'+lang) for subevent in events]):
-                setattr(super_event, 'name_'+lang, super_event_name)
+                update_dict['name_'+lang] = super_event_name
         first_event = events.order_by('start_time').first()
-        super_event.start_time = first_event.start_time
-        super_event.has_start_time = first_event.has_start_time
+        update_dict['start_time'] = first_event.start_time
+        update_dict['has_start_time'] = first_event.has_start_time
+
         last_event = events.order_by('-end_time').first()
-        super_event.end_time = last_event.end_time
-        super_event.has_end_time = last_event.has_end_time
-        super_event.save()
+        update_dict['end_time'] = last_event.end_time
+        update_dict['has_end_time'] = last_event.has_end_time
+
+        if any([value != getattr(super_event, key) for key, value in update_dict.items()]):
+            # if something changed, update
+            for key, value in update_dict.items():
+                setattr(super_event, key, value)
+            super_event.save()
 
     def _synch_events(self, events):
         event_list = sorted(events.values(), key=lambda x: x['start_time'])
['events/importer/lippupiste.py']