Fix bug (encore)

src/agenda_culturel/models.py

@@ -1165,6 +1165,7 @@ class Event(models.Model):
             messages = self.get_contributor_message()
             logger.warning("messages: ")
             logger.warning(messages)
+            if messages:
                 for message in messages:
                     if message and not message.closed and message.email:
                         # send email