[residentadvisor] handles empty price

Sam/sites/residentadvisor.pm

@@ -23,11 +23,14 @@ def weboob_get(id):
 
     event = backends['residentadvisor'].get_event(id)
 
-    return {'title': event.summary,
+    result = {'title': event.summary,
             'day': event.start_date.strftime('%d'),
             'month': event.start_date.strftime('%m'),
             'year': event.start_date.strftime('%Y'),
             'place': event.location,
-            'desc': '%i euros' % event.price,
             'url': event.url}
 
+    if event.price:
+        result['desc'] = '%i euros' % event.price
+
+    return result