BUG/MINOR: stats: Apply proper styles in HTML status page.

BUG/MINOR: stats: Apply proper styles in HTML status page.

When a backend is in status DOWN and going UP it is currently displayed
as yellow ("active UP, going down") instead of orange ("active DOWN, going
UP"). This patches restyles the table rows to actually match the
legend.

This may be backported to any version, the issue appeared in 1.7-dev2
with commit 0c378efe8 ("MEDIUM: stats: compute the color code only in
the HTML form").

(cherry picked from commit 39272c28bffcf57c050703b356c9381df454dea7)
Signed-off-by: Willy Tarreau <w@1wt.eu>