Remove options on local_settings.py (archweb)

This option is no longer required (and it causes conflicts) on Django
versions >= 1.8.

roles/archweb/templates/local_settings.py.j2

@@ -28,7 +28,6 @@ DATABASES = {
         'USER'    : '{{ archweb_db_site_user }}',
         'PASSWORD': '{{ archweb_db_site_password }}',
         'OPTIONS' : {
-            'autocommit': True,
             'application_name': 'archweb',
 {% if archweb_db_host != 'localhost' %}
             'sslmode': 'require',