function content_lock_content_lock_skip_locking excluding valid node type of "user"

If one has a content type of "user", which is valid in D7 (and D8 and 9 I presume), the above noted function will not allow locks on that content type, as 'user' is in its $node_type_blacklist. I suspect this is a left-over from D6 or earlier, but should probably be removed.