Update angular filter to fix null filter.

Due to the changes in
angular/angular.js@71fc3f4
angular/angular.js@d19504a

xref angular/angular.js#11959

Author: samccone

examples/angularjs/js/controllers/todoCtrl.js

@@ -23,10 +23,9 @@ angular.module('todomvc')
 		// Monitor the current route for changes and adjust the filter accordingly.
 		$scope.$on('$routeChangeSuccess', function () {
 			var status = $scope.status = $routeParams.status || '';
-
 			$scope.statusFilter = (status === 'active') ?
 				{ completed: false } : (status === 'completed') ?
-				{ completed: true } : null;
+				{ completed: true } : {};
 		});
 
 		$scope.addTodo = function () {