title: How to remove duplicate options from drop down in select2
body: <p>Hello everyone  i am using select2 plugin from multiselect drop where i am binding values through model but i am getting duplicates values in the dropdown. where i need to remove those duplicates from the dropdown.</p>
  
  <p>This is my dropdown:</p>
  
  <pre><code>    &lt;div class="col-lg-3 col-sm-6"&gt;
      &lt;div class="form-group"&gt;
         &lt;select name="WhoAmIs" id="WhoAmIs" ng-model="data.WhoAmIs" class="form-control whoAmIDuplicates" multiple&gt;
            @foreach (var whoamiall in Model.WhoAmI)
             {
               foreach (var whoami in whoamiall.WhoAmIAll)
               {
                 &lt;option value="@whoami.Name"&gt;@whoami.Name&lt;/option&gt;
               }
             }
          &lt;/select&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>and this is my jquery:</p>
  
  <pre><code>jQuery("#WhoAmIs").select2({
                  maximumSelectionLength: 3,
                  placeholder: jsResources.BusinessDirectory.SelectGroups+' '+ '('+jsResources.BusinessDirectory.Limit+'  '+'3)',
                  allowClear: true
              });
  </code></pre>
  
  <p>i tried  this it is removing multiple values but commenting my jquery in the code</p>
  
  <pre><code>$(".whoAmIDuplicates option").val(function(idx, val) {
                //alert("hi" +" "+ val);
                  $(this).siblings("[value='"+ val +"']").remove();
              });
  </code></pre>