Merge pull request #1405 from christopher-ramirez/master

fix(iuSelectMultiple): add check prior to mutating immutable property

The `_findApproxDupe` was throwing an error when the `isTag` property was being added to a primitive value. These types of values are received when $select.selected holds an array of privitive values (using key binding).

Author: aaronroberson

src/uiSelectMultipleDirective.js

@@ -383,9 +383,11 @@ uis.directive('uiSelectMultiple', ['uiSelectMinErr','$timeout', function(uiSelec
             // handle the object tagging implementation
             } else {
               var mockObj = tempArr[i];
-              mockObj.isTag = true;
+              if (angular.isObject(mockObj)) {
+                mockObj.isTag = true;
+              }
               if ( angular.equals(mockObj, needle) ) {
-              dupeIndex = i;
+                dupeIndex = i;
               }
             }
           }