Fixes group stage missing name

tournaments/templates/tournaments/matches.html

@@ -12,7 +12,7 @@
     <nav class="margin10">
         <a href="{% url 'tournament' tournament.id %}" class="mybox topmargin5">Tous les matchs</a>
         {% for group_stage in group_stages %}
-            <a href="{% url 'tournament' tournament.id %}?group_stage={{ group_stage.id }}" class="mybox topmargin5">{{ group_stage.name }}</a>
+            <a href="{% url 'tournament' tournament.id %}?group_stage={{ group_stage.id }}" class="mybox topmargin5">{{ group_stage.display_name }}</a>
         {% endfor %}
         {% for round in rounds %}
             <a href="{% url 'tournament' tournament.id %}?round={{ round.id }}" class="mybox topmargin5">{{ round.name }}</a>