last 2 major releases of libwurfl included a complete review of engine options with
the result of deprecating many features. The patch removes unecessary code and fixes
the documentation.
Can be backported on any version of haproxy.
[wt: must not be backported since it removes config keywords and would
thus break existing configurations]
Signed-off-by: Willy Tarreau <w@1wt.eu>