Fix crash again

tournaments/models/tournament.py

@@ -545,7 +545,7 @@ class Tournament(models.Model):
     def last_started_match(self):
         matches = [m for m in self.all_matches(False) if m.start_date]
         matches.sort(key=lambda m: m.start_date, reverse=True)
-        return matches.get(0) # get returns None if not present
+        return matches[0] if matches else None
 
     def round_for_index(self, index):
         return self.round_set.filter(index=index, parent=None).first()
@@ -553,7 +553,7 @@ class Tournament(models.Model):
     def first_round(self):
         main_rounds = list(self.round_set.filter(parent=None))
         main_rounds.sort(key=lambda r: r.index, reverse=True)
-        return main_rounds.get(0) # get returns None if not present
+        return main_rounds[0] if main_rounds else None
 
     def broadcasted_group_stages_matches(self):
         matches = []