BUG/MINOR: tcpcheck: Don't warn on unused rules if check option is after

When tcp-check or http-check rules are used, if the corresponding check option
(option tcp-check and option httpchk) is declared after the ruleset, a warning
is emitted about an unused check ruleset while there is no problem in reality.

This patch must be backported as far as 2.2.
diff --git a/src/check.c b/src/check.c
index 0203e3e..63869b9 100644
--- a/src/check.c
+++ b/src/check.c
@@ -1599,6 +1599,7 @@
 	free_tcpcheck_vars(&rules->preset_vars);
 	rules->list = &rs->rules;
 	rules->flags |= TCPCHK_RULES_TCP_CHK;
+	rules->flags &= ~TCPCHK_RULES_UNUSED_TCP_RS;
 
   out:
 	return err_code;
@@ -2621,6 +2622,7 @@
 
 	rules->list = &rs->rules;
 	rules->flags |= TCPCHK_RULES_HTTP_CHK;
+	rules->flags &= ~TCPCHK_RULES_UNUSED_HTTP_RS;
 	if (!tcpcheck_add_http_rule(chk, rules, &errmsg)) {
 		ha_alert("parsing [%s:%d] : '%s %s' : %s.\n", file, line, args[0], args[1], errmsg);
 		rules->list = NULL;