What are the really use of the ancient Project Application issue queue now that you can promote your own sandbox projects?
Apart from your actual question, you also posted a comment which contains this:


  ... the project is promoted, but now how can I obtain the shield?


Not sure if it will be a complete answer to your question, but your scenario here seems a variation of the question about "Why has my security shield for my new module on Drupal.org been removed?". Your variation now seems to be "Why has my security shield for my new module on Drupal.org not yet been added?" (or why is it not visible yet).

Here is part of my answer in that related question:


  You need to create an official release, for at least 1 version of Drupal core that is supported. In your case, for D7, like a 7.x-1.0 version of your module. Shortly after doing so, your module will have the security shield.


I'm not sure (yet) about how long that Shortly actually may take, but I also noticed that on the revisions page of OnlyOne the most current timestamp is 13 Mar 2017 at 22:32 CET (which is less then 24 hours ago). Moreover, on its project page there is also Last modified: March 14, 2017 (which is today ...). But it could well be that with only a little patience (like until tomorrow?), you will automagically get the shield that you're looking for.

Update

Debugging is the art of taking away all possible causes ... about a day later it appears that for your module "a little patience" is not the solution (the shield still doesn't show up). Sorry.