Fix issue #1353 - the management API should listen on 0.0.0:8080

etc/emq.conf

@@ -534,7 +534,7 @@ listener.wss.external.certfile = {{ platform_etc_dir }}/certs/cert.pem
 ##--------------------------------------------------------------------
 ## HTTP Management API Listener
 
-listener.api.mgmt = 127.0.0.1:8080
+listener.api.mgmt = 0.0.0.0:8080
 
 listener.api.mgmt.acceptors = 4