Fix bug preventing "no submissions" message to be shown in some cases

Author: stefano-maggiolo

cms/server/contest/templates/macro/submission.html

@@ -69,7 +69,8 @@
         </tr>
     </thead>
     <tbody>
-    {% if submissions|length == 0 %}
+    {% set num_displayed = submissions|selectattr("official")|list|length if official else submissions|rejectattr("official")|list|length > 0 %}
+    {% if num_displayed == 0 %}
         <tr>
             <td colspan="{{ num_cols }}" class="no_submissions">{% trans %}no submissions{% endtrans %}</td>
         </tr>