title: FileInterceptor doesn't work
body: <p>What am I doing wrong?</p>
  
  <pre><code>@Post('upload')
  @UseInterceptors(FileInterceptor('file'))
      async upload( @UploadedFile() file) {
        console.log(file)
      }
  </code></pre>
  
  <p>file is <code>undefined</code></p>
  
  <p><img src="https://i.stack.imgur.com/U6y2k.png" alt="postman"></p>