bug: Cannot auto config reload after adding host on Gate Lite

[noticebrick]

Before:

config:
  lite:
    enabled: true
    routes:
      - host: server1.example.com
        backend: localhost:25566

After:

config:
  lite:
    enabled: true
    routes:
      - host: server1.example.com
        backend: localhost:25566
      - host: server2.example.com
        backend: localhost:25567

Error:

2024-06-24T01:20:41.556+0800    INFO    reload/watch.go:26      auto-reloading config   {"path": "/root/gate/config.yml"}
2024-06-24T01:20:41.558+0800    INFO    config  gate/gate.go:289        config validation warn  {"warn": "java: No backend servers configured."}
2024-06-24T01:20:41.558+0800    INFO    java    proxy/proxy.go:315      registered builtin commands     {"count": 3, "cmds": ["server", "glist", "send"]}
2024-06-24T01:20:41.558+0800    INFO    reload/watch.go:32      reloaded config successfully    {"path": "/root/gate/config.yml", "duration": "1ms"}

The configuration works after restarted manually.

Please ask me if any additional information is needed.