[CLEANUP] config: catch and report some possibly wrong rule ordering

There are some configurations in which redirect rules are declared
after use_backend rules. We can also find "block" rules after any
of these ones. The processing sequence is :
  - block
  - redirect
  - use_backend

So as of now we try to detect wrong ordering to warn the user about
a possibly undesired behaviour.
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index ec9d23a..6d10b46 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -564,6 +564,7 @@
 		rule->action = action;
 		LIST_INIT(&rule->list);
 		LIST_ADDQ(&curpx->tcp_req.inspect_rules, &rule->list);
+		acl_seen |= CFG_ACL_TCP;
 		return warn;
 	}