sort() doesn't return the list.

automation/services/update-netbox-tool.py

@@ -144,7 +144,8 @@ def add_netbox_device(enb: ElementalNetbox, dev: dict) -> None:
 
     ip_obj.assigned_object_id = dev_intf.id
     ip_obj.assigned_object_type = "dcim.interface"
-    ip_obj.custom_fields["CNAMEs"] = ",".join(dev["aliases"].sort())
+    dev["aliases"].sort()
+    ip_obj.custom_fields["CNAMEs"] = ",".join(dev["aliases"])
     ip_obj.save()
 
     dev_obj.primary_ip4 = ip_obj.id
@@ -213,7 +214,8 @@ if __name__ == "__main__":
                 if not cnames:
                     cnames = ""
 
-                cname_str = ",".join(dev["aliases"].sort())
+                dev["aliases"].sort()
+                cname_str = ",".join(dev["aliases"])
 
                 if cname_str == cnames:
                     create_new = False