google apps script web app verify ownership

问题

We registered and published a web app built with google apps script using UiApp, in the Chrome web store (CWS) a few weeks ago, without any problem. Here is the link to this item just in case http://app.thexs.ca/xsMerge

Now when I go to edit this item CWS is asking for website verification through google webmaster tools for the Url associate with this web app as shown below: https://script.google.com/a/macros/thexs.ca/s/AKfycbzJ3owOK0pzCLfLTNHBQXNSWWlPFwQm2cf5EzTGwgwr24BtY43W/exec

This Url history in webmaster tools shows "Verification succeeded" 31 days ago, but also shows "Reverification failed. We couldn't find the verification meta tag" 2 days ago.

I have no idea how to do that ownership verification in this case

Regards, Fausto

EDIT 1: Just in case this can bring more light to this problem, here is how manifest.json looks like for this web app:

{
  "name": "xsMerge",
  "description": "Merging your Contacts & Lists with Custom Documents, Web pages and Emails.",
  "version": "1.101",
  "manifest_version": 2,
  "icons": {
    "128": "xsMerge-128.png"
  },
  "app": {
    "urls": [
      "https://script.google.com/a/macros/thexs.ca/s/AKfycbzJ3owOK0pzCLfLTNHBQXNSWWlPFwQm2cf5EzTGwgwr24BtY43W/exec"
    ],
    "launch": {
      "web_url": "https://script.google.com/a/macros/thexs.ca/s/AKfycbzJ3owOK0pzCLfLTNHBQXNSWWlPFwQm2cf5EzTGwgwr24BtY43W/exec"
    }
  }
}

来源：https://stackoverflow.com/questions/13807162/google-apps-script-web-app-verify-ownership