Adapt verbosity of some scripts

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>

management/commands/extract_ml_registrations.py

@@ -25,6 +25,10 @@ class Command(BaseCommand):
     def handle(self, *args, **options):
         # TODO: Improve the mailing list extraction system, and link it automatically with Mailman.
 
+        if options['verbosity'] == 0:
+            # This is useless, but this what the user asked.
+            return
+
         if options["type"] == "members":
             for membership in Membership.objects.filter(
                 club__name="BDE",