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#### Describe the issue
I can't post FormData since `"axios": "^0.25.0",`

`Error: Request failed with status code 400`

#### Example Code
```js
export const client = axios.create({
        baseURL: URL_API,
        withCredentials: true,
        responseType: 'json',
	timeout: 30000,
});

const params = new FormData();

params.append('name', data.model);
params.append('idFuel', data.idFuel);
params.append('power', data.idPower);

client.post(`/app/society/${idSociety}/vehicle`, params, { headers: { "Content-Type": "multipart/form-data" } })
```

#### Expected behavior, if applicable
That it works

#### Environment
 - Axios Version: 0.25.0
 - Node.js Version: v14.17.6
 - OS: iOS 15, Android 11 (But on all platforms and versions)
 - Additional Library Versions: React Native 0.64.3

#### Additional context/Screenshots
No problem with  `"axios": "^0.24.0",`

I saw this PR https://github.com/axios/axios/pull/3757 on 0.25.0, but I don't know what I have to change in code.

Thanks for your help 👍

lib/adapters/http.js
'use strict';
var utils = require('./../utils');
var settle = require('./../core/settle');
var buildFullPath = require('../core/buildFullPath');
var buildURL = require('./../helpers/buildURL');
var http = require('http');
var https = require('https');
var httpFollow = require('follow-redirects').http;
var httpsFollow = require('follow-redirects').https;
var url = require('url');
var zlib = require('zlib');
var VERSION = require('./../env/data').version;
var createError = require('../core/createError');
var enhanceError = require('../core/enhanceError');
var defaults = require('../defaults');
var Cancel = require('../cancel/Cancel');
var isHttps = /https:?/;
/**
 *
 * @param {http.ClientRequestArgs} options
 * @param {AxiosProxyConfig} proxy
 * @param {string} location
 */
function setProxy(options, proxy, location) {