Error 400: PHP 5.4 applications cannot be deployed to Google App Engine

This is my file app.yaml

:

application: xxxxxxxxxxxxx
version: 1
runtime: php55
api_version: 1
threadsafe: true

handlers:

- url: /images
  static_dir: images

- url: /css
  static_dir: css

- url: /js
  static_dir: js

- url: /libraries
  static_dir: libraries

- url: /
  script: main.php

# Serve PHP s.
- url: /(.+\.php)$
  script: \1

      

        
        
        
      

    

This is the error I am getting:

Error 400: --- start server output ---

PHP 5.4 applications cannot be deployed to Google App Engine from any SDK version, including older ones. If you need to continue deploying PHP 5.4 applications for compatibility reasons, you can request that your application be whitelisted for PHP 5.4 deployment by visiting http://goo.gl/qjKEuk .

--- exit destination server ---

Can someone please tell me why I am still getting this error after changing runtime

from php

to php55

to app.yaml

?