accessLog can not parse tiple pb idl request

[yangzhongj]

• I have searched the issues of this repository and believe that this is not a duplicate.

Environment

• Dubbo version: 3.1.0
• Operating System version: macos
• Java version: 1.8

Steps to reproduce this issue

1. accesslog = true

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

Expected Behavior

normal print accessLog

Actual Behavior

[yangzhongj]

[AlbumenJ]

This is a bug of fastjson. See alibaba/fastjson#2366

Try configure -Ddubbo.json-framework.prefer=gson to bypass this.

In Dubbo 3.2, Dubbo will use fastjson2 as default and no longer depend on fastjson. Fastjson2 has fix this in 2.0.16.