Add specific class for "add" list item

src/Umbraco.Web.UI.Client/src/views/propertyeditors/mediapicker/mediapicker.controller.js

@@ -137,7 +137,7 @@ angular.module('umbraco').controller("Umbraco.PropertyEditors.MediaPickerControl
 
        $scope.sortableOptions = {
            disabled: !$scope.isMultiPicker,
-           items: "li:not(.unsortable)",
+           items: "li:not(.add-wrapper)",
            cancel: ".unsortable",
            update: function(e, ui) {
                var r = [];

src/Umbraco.Web.UI.Client/src/views/propertyeditors/mediapicker/mediapicker.html

@@ -30,7 +30,7 @@
                 </div>
 
             </li>
-            <li class="unsortable" ng-if="showAdd()">
+            <li class="add-wrapper unsortable" ng-if="showAdd()">
                 <a href="#" class="add-link" ng-click="add()" ng-class="{'add-link-square': (images.length === 0 || isMultiPicker)}" prevent-default>
                     <i class="icon icon-add large"></i>
                 </a>