在org.apache.servicecomb.common.rest.RestEngineSchemaListener注册之前 kafka消费消息调用接口，导致后续调用该接口都报空指针异常

```
2022-07-28 14:36:45.020|[]|mock-thread|WARN |SCBEngine.java:513|The request is rejected. Cannot process the request due to STATUS = STARTING
2022-07-28 14:36:45.020|[]|mock-thread|WARN |VehicleTaskEndListener.java:64|clear busyTag of [335157342402481152] failed
2022-07-28 14:36:45.215|[]|mock-thread|INFO |MicroserviceVersions.java:93|create MicroserviceVersions, appId=mockAppId, microserviceName=mockMicro.
2022-07-28 14:36:46.125|[]|main|INFO |SCBEngine.java:630|instance registry succeeds for the first time, will send AFTER_REGISTRY event.
```

`create MicroserviceVersions`日志打印早于`instance registry succeeds for the first time`

通过日志上下文可以确定这个日志是调用一个@RpcReference的接口触发的。但是按理`currentStatus` 不为UP调用接口应该会抛错。

从 SCBEngine.java 中 STARTING 状态检查和第一个实例注册事件附近开始，然后跟踪在 RestEngineSchemaListener 注册之前调用 @RpcReference 接口的 Kafka consumer 路径。使用提供的日志顺序来复现生命周期竞态。完成的标准是：早期调用能够得到一致处理，后续调用不再因空指针异常而失败。

由索引模型根据 Issue 内容生成。