title: ng-model value with multi-select disappears on refresh when only one value selected
body: <p>I have the following Angular code:</p>
  <pre><code>        &lt;select
                  class=&quot;form-control chosen-select ng-pristine ng-untouched ng-scope localytics-chosen ng-valid ng-valid-required&quot;
                  chosen
                  multiple
                  data-placeholder=&quot;Select Field&quot;
                  ng-options=&quot;value for (key, value) in plugin.allCollections&quot;
                  ng-model=&quot;plugin.item.collections&quot;
                  id=&quot;{{plugin.context}}collections&quot;&gt;
          &lt;/select&gt;
  </code></pre>
  <p>Where <code>plugin.allCollections</code> is an object of the form</p>
  <pre><code>{
    3938757: &quot;some collection&quot;,
    3932012: &quot;some other collection&quot;
  }
  </code></pre>
  <p>In which the keys are numerical, and I only want to save the text values to <code>plugin.item.collections</code>.</p>
  <p>It seems to be working insofar as when I save, I properly receive the string values as an array in the backend.</p>
  <p>However, if I only select one collection, and then save it, it seems the single collection remains bound to the object (i.e. if I console log <code>plugin.item.collections</code> I will see <code>[&quot;some collection&quot;]</code> as expected) -- but it disappears from the UI on refresh. BUT if I have more than one selected/saved, they won't disappear on refresh.</p>
  <p>What's causing this difference in behavior, and how can I stop the value from disappearing when only one is selected?</p>