backups: Remove cancel button from add disk location page

For consistency with add remote location page.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/backups/templates/backups_add_repository.html

@@ -32,9 +32,6 @@
 
     <input type="submit" class="btn btn-primary"
            value="{% trans "Create Repository" %}"/>
-    <a class="btn btn-default" role="button" href="{% url 'backups:index' %}">
-      {% trans "Cancel" %}
-    </a>
   </form>
 
 {% endblock %}