**To Reproduce**
Code snippet to reproduce, ideally that will work by pasting into something like https://npm.runkit.com/axios, a hosted solution, or a repository that illustrates the issue. 

```js
const axios = require("axios")

const url = 'https://stackoverflow.com/questions';

const {headers} = await axios.head(url, {
  headers: {'accept-encoding': 'gzip, deflate, br'}
});
```
You can run this in one click here https://runkit.com/embed/eocb5097ds6r
 
**Expected behavior**
Don't crush

**Environment:**
 - Node.js any version

**Solution:**
It require trivial fix similar to https://github.com/axios/axios/pull/1129
lib/adapters/http.js
var urlUsername = urlAuth[0] || '';
      var urlPassword = urlAuth[1] || '';
      auth = urlUsername + ':' + urlPassword;
    }
    if (auth) {
      delete headers.Authorization;
    }
    var isHttpsRequest = isHttps.test(protocol);
    var agent = isHttpsRequest ? config.httpsAgent : config.httpAgent;
    var options = {
      path: buildURL(parsed.path, config.params, config.paramsSerializer).replace(/^\?/, ''),
      method: config.method.toUpperCase(),
      headers: headers,
      agent: agent,
      agents: { http: config.httpAgent, https: config.httpsAgent },
      auth: auth
    };
    if (config.socketPath) {
      options.socketPath = config.socketPath;
    } else {
      options.hostname = parsed.hostname;
      options.port = parsed.port;
    }
    var proxy = config.proxy;
    if (!proxy && proxy !== false) {
      var proxyEnv = protocol.slice(0, -1) + '_proxy';
      var proxyUrl = process.env[proxyEnv] || process.env[proxyEnv.toUpperCase()];
      if (proxyUrl) {
        var parsedProxyUrl = url.parse(proxyUrl);
        var noProxyEnv = process.env.no_proxy || process.env.NO_PROXY;