There is ambiguity in --host 0.0.0.0 from playground

[hackersean]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?

 tiup playground  --host 0.0.0.0  --monitor

2. What did you expect to see?
   tiup chose an ip in host,like 10.0.2.4. when i connect 127.0.0.1:4000 will be rejected. it is not expected. only can use 10.0.2.4:4000

CLUSTER START SUCCESSFULLY, Enjoy it ^-^
To connect TiDB: mysql --host 10.0.2.4 --port 4000 -u root -p (no password) --comments
To view the dashboard: http://10.0.2.4:2379/dashboard
PD client endpoints: [10.0.2.4:2379]
To view the Prometheus: http://10.0.2.4:9090
To view the Grafana: http://10.0.2.4:3000

3. What did you see instead?
   when a server is told to listen on 0.0. 0.0 that means "listen on every available network interface"。

in stdout,print a local ip.

4. What version of TiUP are you using (tiup --version)?

1.5.3 tiup
Go Version: go1.16.5
Git Ref: v1.5.3
GitHash: 222bd4d460eaa3fb6feec6ddeb8612fe0870ffd3