Google在PHP应用程序引擎中找不到Robots.txt

Question

由于我一直在robots.txt上收到404错误，因此Googlebot找不到我的Stack Logger文件。

我的应用程序的结构如下：

/www
    - index.html
    - sendMessage.php
app.yaml
robots.txt

这是我的app.yaml文件：

runtime: php55
service: default
api_version: 1
threadsafe: true
automatic_scaling:
   min_idle_instances: 1
instance_class: F4_1G

handlers:
- url: /sendMessage.php
  script: sendMessage.php
  secure: always 

- url: /
 static_files: www/index.html
 upload: www/index.html
 secure: always

- url: /robots.txt
  static_files: robots.txt
  upload: robots.txt

- url: /(.*)
static_files: www/\1
upload: www/(.*)
secure: always

然后我的robots.txt文件是：

# Rule 1
User-agent: Googlebot
Disallow: /nogooglebot/

# Rule 2
User-agent: *
Allow: /

任何帮助将不胜感激！谢谢:)