LENGTH? spec says NONE can be returned

[gurzgri]

But LENGTH? on port will always return 0 if port actor tries to return none:

register-scheme make system/standard/scheme [name: 'len actor: context [
    open: func [port] [port]
    length?: func [port] [none]
]]
length? port: open len://test ;== 0

So it's an issue with the docstring, as per red/red@a063f13 the signature has been changed from return: [red-value!] to return: [integer!].

Red 0.6.4 for Windows built 15-Apr-2022/10:42:52+02:00 commit #502097e