Fixed statistics module to exclude empty (not null) URLs

boards/management/commands/statistics.py

@@ -11,7 +11,7 b' class Command(BaseCommand):'
     def handle(self, *args, **options):
         print('* Domains and their usage')
         domains = {}
-        for attachment in Attachment.objects.exclude(url=None):
+        for attachment in Attachment.objects.exclude(url=None).exclude(url=''):
             full_domain = attachment.url.split('/')[2]
             domain = get_domain(full_domain)
             if domain in domains: