- [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-SNAPSHOT
* Operating System version: macOs
* Java version: JDK 1.8

### Steps to reproduce this issue

1. Assume Demo interface have sayHello and sayHi method. 
```
<dubbo:reference id="demoService" interface="com.ctrip.Demo" timeout="1000">
  <dubbo:method name="sayHello">
    <dubbo:parameter key="timeout" value="800"/>
  </dubbo:method>
</dubbo:reference>
```
2. Make a sync call to sayHello, the timeout is 800 but not 1000. We have not get method timeout from the url.

```
asyncResult.get(getUrl().getParameter(TIMEOUT_KEY, DEFAULT_TIMEOUT), TimeUnit.MILLISECONDS);
```

Pls. provide [GitHub address] to reproduce this issue.

### Expected Result

The timeout should be 1000 for sayHello.

### Actual Result

The timeout is 800 for sayHello.

If there is an exception, please attach the exception trace:

```
Just put your stack trace here!
```

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package org.apache.dubbo.rpc.protocol.dubbo;
import org.apache.dubbo.common.URL;
import org.apache.dubbo.common.config.ConfigurationUtils;
import org.apache.dubbo.common.utils.AtomicPositiveInteger;