Only allow webmasters to create 'Drupal.org' projects

Currently any Git user can create project node of type 'Drupal.org project'. Very often it is done by mistake. Huge portion of Drupal.org projects, especially the ones created in the last year, has little to do with Drupal.org and should be a regular module project. There are very few cases when creation of 'Drupal.org project' is justified and it can be requested as needed. Thus let's move the permission to create this type of projects up to Webmasters.