Found problem in code

[ZhangWei88]

Hi dear.

How are you?
I have found a problem in the source code so would like to notice to you.
I tried to use async data load function for multiselect but got javascript error whenever open dropdown.
So I checked the source code of multiselect and found there is a problem.
I think you should replace these lines :

$scope.toggleDropdown = function () {
      $scope.open = !$scope.open;
      $scope.resolvedOptions = $scope.options;
      updateSelectionLists();
};

by these lines :

$scope.toggleDropdown = function () {
      $scope.open = !$scope.open;
      if (typeof $scope.options !== 'function') {
            $scope.resolvedOptions = $scope.options;
      }
      updateSelectionLists();
};

I think this problem had been made when fix the issue #21 .
I hope this report would help you even a little.

Thanks,
Zhang