bundles/nginx: do not try to get reltsenrypt certificates for non-domains

bundles/nginx/metadata.py

@@ -73,6 +73,10 @@ def letsencrypt(metadata):
     for vhost, config in metadata.get('nginx/vhosts', {}).items():
         if config.get('ssl', 'letsencrypt') == 'letsencrypt':
             domain = config.get('domain', vhost)
+
+            if '.' not in domain:
+                continue
+
             domains[domain] = config.get('domain_aliases', set())
             vhosts[vhost] = {
                 'ssl': 'letsencrypt',