title: React select with value null
body: <p>I have the following code as part of my React component:</p>
  
  <pre><code>&lt;select
    className="input form-control"
    onChange={this.onUserChanged}
    value={task.user_id}&gt;
    &lt;option value=''&gt;&lt;/option&gt;
    {this.renderUserOptions()}
  &lt;/select&gt;
  </code></pre>
  
  <p>When the task.user_id is null on the first rendering of the component, the select is properly displayed with the empty option with value <code>''</code>.</p>
  
  <p>However, if I change the value from something that has a value back to the default option, the server side updates correctly, the task object returns the <code>null</code> for <code>task.user_id</code> but the select doesn't change to the default value.</p>
  
  <p>What should I do to handle this scenario?</p>
  
  <hr>