Dear Remi, I ran those commands you suggested in lava shell and it printed as below :
Python 3.5.3 (default, Jan 19 2017, 14:11:04)
[GCC 6.3.0 20170118] on linux
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
from django.contrib.sites.models import Site
Site.objects.all()
<QuerySet [<Site: 192.168.100.103>]>
Site.objects.count()
1