DOC: Fix documentation about the cli command to get resolver stats

In the management guide, this command was still referenced as "show stat
resolvers" instead of "show resolvers". The cli command was fixed by the commit
ff88efbd7 ("BUG/MINOR: dns: Fix CLI keyword declaration").

This patch fixes the issue #296. It can be backported as fas as 1.7.

(cherry picked from commit 78c430616552e024fc1e7a6650302702ae4544d1)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
1 file changed