The incubating label should be removed from all mentions of the 1.5.3 version.
I have changed it in source, but I can't find a way to change or rather create new labels without "incubating" in JIRA.
You don't have admin rights in jira. Othrwise there would be an "Administration" link next to the "Quick Search" text field.
I changed it now. So we can close the issue.