fix(lockedItems): Properly unlock locked items when lock conditions change

Previously when the lock expression value changes from true to false the locked value was not removed from the locked list.

Closes angular-ui#1824

Author: jasonthomasgray

src/uiSelectController.js

@@ -430,7 +430,7 @@ uis.controller('uiSelectCtrl',
             ctrl.close(skipFocusser);
             return;
           }
-        }        
+        }
         _resetSearchInput();
         $scope.$broadcast('uis:select', item);
 
@@ -506,7 +506,7 @@ uis.controller('uiSelectCtrl',
         }
 
       if (!isLocked && lockedItemIndex > -1) {
-        lockedItems.splice(lockedItemIndex, 0);
+        lockedItems.splice(lockedItemIndex, 1);
       }
     }