ci: Fix database engine

snf-deploy/files/etc/synnefo/webproject.conf

@@ -7,7 +7,7 @@ make_psycopg_green()
 DATABASES = {
  'default': {
      # 'postgresql_psycopg2', 'postgresql','mysql', 'sqlite3' or 'oracle'
-     'ENGINE': 'postgresql_psycopg2',
+     'ENGINE': 'django.db.backends.postgresql_psycopg2',
       # ATTENTION: This *must* be the absolute path if using sqlite3.
       # See: http://docs.djangoproject.com/en/dev/ref/settings/#name
      'OPTIONS': {