title: react-native how to catch warning in release
body: <pre><code>constructor(props) {
      super(props);
      this.state = {
          encryptInfo: '',
          testKey:this.props.test.key,
      };
  }
  </code></pre>
  
  <p>if this.props.test.key is undefined </p>
  
  <p>in debug mode，it will show [warn] in xcode terminal and show YellowBox，</p>
  
  <p>but if in release I can't get any info</p>
  
  <p>and I try to rewrite <code>console.warn</code>  it also no use in release.</p>
  
  <p>Is any way catch warning in release ?</p>