org.apache.dubbo.remoting.TimeoutException: Waiting server-side response timeout by scan timer. start time: 2021-08-15 23:04:35.615, end time: 2021-08-15 23:05:06.234, client elapsed: 20491 ms, server elapsed: 10128 ms, timeout: 100 ms

- [x] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.
- [x] I have checked the [FAQ](https://github.com/apache/dubbo/blob/master/FAQ.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: 2.7.3
* Operating System version: Red Hat 4.8.5
* Java version: openjdk8

### Steps to reproduce this issue

It happened online. I tried it locally and couldn't replicate it.

online log:
```log
org.apache.dubbo.remoting.TimeoutException: Waiting server-side response timeout by scan timer. start time: 2021-08-15 23:04:35.615, end time: 2021-08-15 23:05:06.234, client elapsed: 20491 ms, server elapsed: 10128 ms, timeout: 100 ms, request: Request
```
A timeline based on online consumer and provider logs:

| client | server |
| :-: | :-: |
| start 1629039875615(2021-08-15 23:04:35.615) | |
| send 1629039896106(2021-08-15 23:04:56.106) | |
| | server biz process start(2021-08-15 23:04:56.106) |
| | server biz process end(2021-08-15 23:04:56.109) |
| received 1629039906234(2021-08-15 23:05:06.234) | |

### Expected Result

Why does the consumer timeout period not take effect

relation issues: #4732 #103