[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!

从 pulsar::HTTPLookupService::handleLookupHTTPRequest 开始，使用 pulsar-cpp-client v2.8.3 和 gcc 7.3.1 重现报告中的 coredump。Issue 表示重现概率较低，并且只提供了截图，因此首先缩小触发该问题的请求或状态范围。完成的标准是确定崩溃原因，并确认 lookup request 不再产生 coredump。

由索引模型根据 Issue 内容生成。