alt-svc: Alt-Used security discussion

[LPardue]

Section 5 foreshadows a discussion about privacy

As the Alt-Used header field might be used by the server for tracking the client, a client MAY choose not to include it in its requests for protecting its privacy (see Section 9.4).

However, Section 9.4 doesn't contain any mention of Alt-Used. Maybe all the information contained in the document is enough but this just struck me as a little odd.

[reschke]

This inconsistency was caused by the fix for #36.

AFAIR, we made this change because the risk of tracking is there no matter whether Alt-Used is sent (see current Section 9.4). Thus, the simplest possible change would be to remove the whole sentence and the misleading forward reference.

[mnot]

SGTM.