[Bug] pulsar-cpp-client pulsar::HTTPLookupService::handleLookupHTTPRequest coredump

### Search before asking

- [X] I searched in the [issues](https://github.com/apache/pulsar/issues) and found nothing similar.

### Version

pulsar-cpp-client v2.8.3 gcc7.3.1

### Minimal reproduce step

The probability is low

### What did you expect to see?

solve this bug

### What did you see instead?

pulsar-cpp-client v2.8.3

### Anything else?

_No response_

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!

從 pulsar::HTTPLookupService::handleLookupHTTPRequest 開始，使用 pulsar-cpp-client v2.8.3 和 gcc 7.3.1 重現回報的 coredump。Issue 表示重現機率較低，且只提供了螢幕截圖，因此首先縮小觸發問題的 request 或狀態範圍。完成的標準是找出 crash 原因，並確認 lookup request 不再產生 coredump。

由索引模型根據 Issue 內容生成。