Handle bad url

urlchecker_bot.py

@@ -54,7 +54,9 @@ class WebBot:
         # Extract the list of URL domains
         url_list = self.calculateUrlList()
         for url in url_list:
-            domain_list.append(getUrlHostname(url))
+            domain = getUrlHostname(url)
+            if domain is not None:
+                domain_list.append(domain)
         domain_list = list(set(domain_list))
 
         # Expand with all parent domains