Fix the bug that the grpc protocol is incompatible with authentication(issue:#3001)

[Paragrf]

…y could not be parsed by the client to get the correct error code after authentication failed

What problem does this PR solve?

Issue Number: #3001

Problem Summary:

What is changed and the side effects?

Changed:

• grpc协议和http协议当前共用同一个鉴权函数，所以在鉴权函数中增加了对http协议类型的判断，如果是http2.0版本，按grpc格式返回错误

Side effects:

• Performance effects:

• Breaking backward compatibility:

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Check List:

• Please make sure your changes are compilable.
• When providing us with a new feature, it is best to add related tests.
• Please follow Contributor Covenant Code of Conduct.

[Paragrf]

Close #3001

[Paragrf]

@chenBright please take a look ：）

[chenBright]

Please add unit test for this case in test/brpc_server_unittest.cpp.

[Paragrf]

Please add unit test for this case in test/brpc_server_unittest.cpp.

@chenBright done

[Paragrf]

@chenBright @wwbmmm please take a look， thx

[Paragrf]

@chenBright hello, can this PR be merged