fixing provides_extra

Signed-off-by: javanlacerda <[email protected]>

Author: javanlacerda

warehouse/admin/templates/admin/projects/release_detail.html

@@ -311,7 +311,7 @@ <h3>Metadata</h3>
           <tr>
           <td>Provides-Extra</td>
           <td>
-            {% for extra in release.provides_extras %}
+            {% for extra in release.provides_extra %}
             <code>{{ extra }}</code><br>
             {% endfor %}
           </td>