Fix invalid warning message from openresty 1.15.8.1
Fix invalid warning message from openresty 1.15.8.1

Signed-off-by: Eloy Coto <2a8acc28452926ceac4d9db555411743254cf5f9@gmail.com>

3scale/docker-gateway,3scale/apicast,3scale/apicast,3scale/docker-gateway,3scale/apicast,3scale/apicast