Editorial: ALTSVC HTTP/2 Frame.

Hi,

I see that the ALTSVC HTTP/2 Frame format has changed from draft-04 to
draft-05.  If I understand correctly, now the HTTP/2 frame cannot
contain an Origin field.  This makes the following two paragraphs in
https://tools.ietf.org/id/draft-ietf-httpbis-alt-svc-05.html#rfc.section.4
moot:

"An ALTSVC frame from a server to a client on stream 0 indicates that
the conveyed alternative service is associated with the origin
contained in the Origin field of the frame. An association with an
origin that the client does not consider authoritative for the current
connection MUST be ignored."

"An ALTSVC frame on a client-initiated stream containing non-empty
"Origin" information is invalid and MUST be ignored. Likewise, an
ALTSVC frame on stream 0 with empty (length 0) "Origin" information is
invalid and MUST be ignored."

If this is the case, then they should be removed and replaced by the text
"An ALTSVC frame MUST not have a stream identifier of 0.".

Please let me know if my understanding is correct.  In this case, I
would be glad to prepare the proposed change on GitHub.  Thank you.

Best wishes,

Bence