packages-list: consistently do not use a '?' in column names

Signed-off-by: Mattia Rizzolo <mattia@debian.org>

debexpo/packages/templates/packages-list.html

@@ -10,7 +10,7 @@
         <th width="30%">{% trans 'Description' %}</th>
         <th width="20%">{% trans 'Version' %}</th>
         <th width="15%">{% trans 'Uploader' %}</th>
-        <th width="10%">{% trans 'Needs a sponsor?' %}</th>
+        <th width="10%">{% trans 'Needs a sponsor' %}</th>
         <th width="10%">{% trans 'Already in Debian' %}</th>
     </tr>