DOC: management: fix typo in commit f4f93c56

DOC: management: fix typo in commit f4f93c56

Fixes a small typo in commit f4f93c56 ("DOC: management: clarify usage
of -V with -c").

Must be backported as far as 2.8 along commit f4f93c56.

(cherry picked from commit faacc6c0842d2409abaf655d1967330af1790048)
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit e4bc87caaa08b3c8fbe46bd8c988aa486b571425)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 33bb9f423f8c14aaf3753724a2d0a492fc8b7c39)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>