astakos: Update django requirements in synnefo settings

since session and messages middleware classes removed from webproject we should
explicitly set them on astakos settings.

snf-astakos-app/astakos/synnefo_settings.py

@@ -67,11 +67,13 @@ context_processors = [
 ]
 
 middlware_classes = [
+    'django.contrib.sessions.middleware.SessionMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
     'astakos.im.middleware.CookieAuthenticationMiddleware',
     'synnefo.lib.middleware.LoggingConfigMiddleware',
     'synnefo.lib.middleware.SecureMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
+    'django.contrib.messages.middleware.MessageMiddleware',
 #    'debug_toolbar.middleware.DebugToolbarMiddleware',
 ]