#### Describe the bug
For some REST API endpoints we use [Google Cloud API Custom Methods](https://cloud.google.com/apis/design/custom_methods) URL design like `/api/resource:customVerb`.

These worked with `axios` prior to **0.27.1** but now they result in an error like:

`AxiosError { message: "Unsupported protocol /api/resource:', code: "ERR_BAD_REQUEST", ... }`

#### To Reproduce
Try to have `axios` get a relative URL with a colon in it, e.g.
```js
axios.get("/api/resource:customVerb");
```

#### Expected behavior
Should continue working as it did before version **0.27.1**.

#### Environment
 - Axios Version: 0.27.1
 - Browser: Microsoft Edge 100.0.1185.50
 - Node.js Version: 16.14.2
 - OS: Windows 10 Pro

#### Additional context/Screenshots
n/a

lib/adapters/xhr.js
if (!request) {
        return;
      }
      
      var responseHeaders = 'getAllResponseHeaders' in request ? parseHeaders(request.getAllResponseHeaders()) : null;
      var responseData = !responseType || responseType === 'text' ||  responseType === 'json' ?
        request.responseText : request.response;
      var response = {
        data: responseData,
        status: request.status,
        statusText: request.statusText,
        headers: responseHeaders,
        config: config,
        request: request
      };
      settle(function _resolve(value) {
        resolve(value);
        done();
      }, function _reject(err) {
        reject(err);
        done();
      }, response);
      
      request = null;
    }
    if ('onloadend' in request) {
      
      request.onloadend = onloadend;