BUG/MINOR: haproxy: Fix option to disable the fast-forward

The option was renamed to only permit to disable the fast-forward. First
there is no reason to enable it because it is the default behavior. Then it
introduced a bug because there is no way to be sure the command line has
precedence over the configuration this way. So, the option is now named
"tune.disable-fast-forward" and does not support any argument. And of
course, the commande line option "-dF" has now precedence over the
configuration.

No backport needed.
6 files changed