fix(typeahead): change to original scope

- Change to original scope for running $digest

Closes #5588
Fixes #5467

Author: wesleycho

src/typeahead/typeahead.js

@@ -401,7 +401,7 @@ angular.module('ui.bootstrap.typeahead', ['ui.bootstrap.debounce', 'ui.bootstrap
           evt.stopPropagation();
 
           resetMatches();
-          scope.$parent.$digest();
+          originalScope.$digest();
           break;
         case 38:
           scope.activeIdx = (scope.activeIdx > 0 ? scope.activeIdx : scope.matches.length) - 1;
@@ -455,7 +455,7 @@ angular.module('ui.bootstrap.typeahead', ['ui.bootstrap.debounce', 'ui.bootstrap
       if (element[0] !== evt.target && evt.which !== 3 && scope.matches.length !== 0) {
         resetMatches();
         if (!$rootScope.$$phase) {
-          scope.$digest();
+          originalScope.$digest();
         }
       }
     };