title: Ionic 3: ng-change doesn't work
body: <p>I have a input field where a user can input his address and get auto-suggestions:</p>
  
  <pre><code> &lt;ion-label color="primary" stacked&gt;Adresse:&lt;/ion-label&gt;
          &lt;ion-input type="text" ng-model="autocomplete.query" ng-change="updateSearch()"&gt;&lt;/ion-input&gt;
  </code></pre>
  
  <p>My class has a update method where i want to do something, but unfortunately he doesn't get into it. </p>
  
  <pre><code>updateSearch()
    {
      console.log('aaa');
      if (this.autocomplete.query == '') {
        this.autocompleteItems = [];
        return;
      }
  }
  </code></pre>
  
  <p>Any ideas?</p>