Request string reprenetations prints non-existing field

tostring(req) invokes request_tostring function, which does the following step:
https://github.com/tarantool/http/blob/6be78efcb2848d740b5c1c16511953a05b328e82/http/server.lua#L170

But request does not have a body attribute. response does. String representation of a request always ends with empty lines since .body == nil.

local log = require('log')

local http_server = require('http.server')

box.cfg{}

local httpd = http_server.new('127.0.0.1', 8081)
httpd:route(
    { path = '/hello', method = 'POST' }, function(req)
        local _ = req:json() -- If removed, result is the same.
        log.info(req.body)
        log.info(tostring(req))
        return req:render{text = 'OK'}
    end)
httpd:start()

curl -X POST localhost:8081/hello?a=a -d '{"sdfs":"dfdfsfs"}'

2023-09-18 10:31:12.506 [1212600] main/114/http/127.0.0.1:60846/http.server I> POST /hello?a=a
2023-09-18 10:31:12.506 [1212600] main/114/http/127.0.0.1:60846/. I> 
2023-09-18 10:31:12.506 [1212600] main/114/http/127.0.0.1:60846/. I> POST /hello?a=a HTTP/1.1
Host: localhost:8081
Content-type: application/x-www-form-urlencoded
Content-length: 18
Accept: */*
User-agent: curl/7.81.0

The request_tostring function is at http/server.lua#L170; read that implementation and compare the request fields with the response fields described in the issue. Reproduce the shown POST route with the provided curl command, then verify that tostring(req) no longer includes the nonexistent body or trailing empty lines.