DOC: clarify the fact that replace-uri works on a full URI

With H2 deployments becoming more common, replace-uri starts to hit
users by not always matching absolute URIs due to rules expecting the
URI to start with a '/'.

(cherry picked from commit 62b5913380d6820bb249672bbf57b9377ceaf9e1)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 28a5eba5ab164ddd073a57b4928589850f7cf9b1)
Signed-off-by: Willy Tarreau <w@1wt.eu>
1 file changed