BUG/MINOR: server: allow 'enable health' only if check configured

Test that checks have been configured on the server before enabling via
the 'enable health' CLI. This mirrors the 'enable agent' command.

Without this, a user can use the command on the server without checks.
This leaves the server in an undefined state. Notably, the stat page
reports the server in check transition.

This condition was left on the following reorg commit.
  2c04eda8b58636ad2ae44e42b1f50f3b5a24a642
  REORG: cli: move "{enable|disable} health" to server.c

This should be backported up to 1.8.

(cherry picked from commit 0f456d502963f3555552d4b3d5f97ed504353d85)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
1 file changed