[BUG] - http请求体开启了压缩之后，cse未能正确识别到

### Steps to Reproduce

1. 发送http请求，http header如下：
```
'Content-Encoding': 'gzip',
'Content-Type': 'application/json',
```
2. 请求发送到服务器端，未能正确先解压gzip，导致报错：
```
Parameter is [queryReq]. Processor is [body]. Message is [Illegal character ((CTRL-CHAR, code 31)): only regular white space (\\r, \\n, \\t) is allowed between tokens\n at [Source: REDACTED (`StreamReadFeature.INCLUDE_SOURCE_IN_LOCATION` disabled); line: 1, column: 2]]."}
```
3. 只有尝试将http请求的header修改为如下的时候，才不会报错：
```
'Content-Encoding': 'gzip',
'Content-Type': 'application/gzip',
```
查找一些资料显示，Content-Type 表示标头用于指示资源的原始[媒体类型](https://developer.mozilla.org/zh-CN/docs/Glossary/MIME_type)（在发送时应用任何内容编码之前）；写成`'Content-Type': 'application/gzip'`也不正确了，原始内容是json格式的body

### Expected Behavior

_No response_

### Servicecomb Version

_No response_

### Additional Context

_No response_

The issue names no source file, test, or entry point. Start by locating HTTP request-body handling and Content-Encoding processing, then reproduce the JSON request with gzip. Done means a gzip-encoded JSON body with Content-Type application/json is decompressed before parsing without the reported error, with regression coverage.

Written by the indexing model from the issue text.