DOC: config: use the word 'backend' instead of 'proxy' in 'track' description

User @nwehrman reported in issue #2328 that the used of "proxy" instead
of "backend" in the argument of the "track" server keyword is confusing.
Admittedly, all other places in the doc use "backend/server" instead of
"proxy/server", so let's update it for the sake of consistency.

(cherry picked from commit 9530e7dcd38f2a771558c75b40c7decf14c1bc7a)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit e54afdcfbab6995f7d3c8260170c83916a4c31b6)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit ea4562e4af9bc5cb880c616c7b17e45a8e3a0f1e)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 94115ba49dac619cdfc10a61fd9c19746b86cdb8)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
1 file changed