DOC: fix discrepancy in the example for http-request redirect

Commit c8f0e78 ("DOC: typo: req.uri is now replaced by capture.req.uri")
fixed a discrepancy in the doc but the scheme is still missing, resulting
in a redirect loop. Let's fix this as well. This should be backported to
1.5.
(cherry picked from commit 596659b023b01d8a81ae262af9ccab5ea2cb313f)
(cherry picked from commit 9b697e6afbbe55e5f00b14d99a535199837a2d5a)
1 file changed