Fix error message.

biscuit/apps/alsijil/templates/alsijil/group_week.html

@@ -115,7 +115,7 @@
       <div class="card-body">
         <p>
           {% blocktrans %}
-            You must select a group to see the week summary.
+            You must select a group, a teacher or a room to see the week summary.
           {% endblocktrans %}
         </p>
       </div>