Updated the number of people involved in the Drupal community

The original 630,000+ figure comes from the (outdated?) 
[drupal.org/about](https://drupal.org/about) page. In the 
[drupal.org](https://drupal.org/) homepage, the (updated?)
figure is 1,006,154 people.
Merge pull request #111 from javiereguiluz/patch-1

Updated the number of people involved in the Drupal community