title: Angular ui-select placeholder not working when ng-model is initialized
body: <p>I am trying to add a new select every time a button is clicked,</p>
  
  <p>The html:</p>
  
  <pre><code> &lt;div ng-repeat = "select in selects track by $index"&gt;
    &lt;ui-select ng-model="selects[$index]" theme="select2" ng-disabled="disabled" style="min-width: 300px;"&gt;
      &lt;ui-select-match placeholder="Select a person in the list or search his name/age..."&gt;{{$select.selected.name}}&lt;/ui-select-match&gt;
      &lt;ui-select-choices repeat="person in people"&gt;
        &lt;div ng-bind-html="person.name | highlight: $select.search"&gt;&lt;/div&gt;
      &lt;/ui-select-choices&gt;
    &lt;/ui-select&gt;
   &lt;/div&gt;
   &lt;button ng-click="addNewSelect()"&gt; Add new select&lt;/button&gt;
  </code></pre>
  
  <p>The controller:</p>
  
  <pre><code>  $scope.selects = [{}];
    $scope.addNewSelect = function() {
      $scope.selects.push({});
    }
  </code></pre>
  
  <p>The array of objects gets saved in the array 'selects', but the placeholder is not coming in the selects as I am initializing the ng-model with an empty object initially. How to get he placeholder working in this case?</p>
  
  <p>Here is the <a href="http://plnkr.co/edit/rtPUe3HwA4F3aNnltBPc?p=preview" rel="nofollow noreferrer">Plunker</a> for the same.</p>