Fix basic auth problem in ActionController::HttpAuthentication::Basic doc

actionpack/lib/action_controller/metal/http_authentication.rb

@@ -56,8 +56,8 @@ module HttpAuthentication
     # In your integration tests, you can do something like this:
     #
     #   def test_access_granted_from_xml
-    #     @request.env['HTTP_AUTHORIZATION'] = ActionController::HttpAuthentication::Basic.encode_credentials(users(:dhh).name, users(:dhh).password)
-    #     get "/notes/1.xml"
+    #     headers = { 'HTTP_AUTHORIZATION' => ActionController::HttpAuthentication::Basic.encode_credentials(users(:dhh).name, users(:dhh).password }
+    #     get "/notes/1.xml", headers: headers
     #
     #     assert_equal 200, status
     #   end