title: How handle "missing message" error in react-intl?
body: <p>I'm using react-intl version 2.4.0 and for some translations I receive  "missing message" error in console. Is there any way to handle them without upgrading to v3?</p>
  
  <pre><code>&lt;IntlProvider
          locale="ru"
          messages={localeData.ru}
        &gt;
          &lt;Layout&gt;
            &lt;Component {...props} /&gt;
          &lt;/Layout&gt;
        &lt;/IntlProvider&gt;
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/4dEHu.png" rel="noreferrer"><img src="https://i.stack.imgur.com/4dEHu.png" alt="enter image description here"></a></p>