Hosting 'Initial Setup' drush command requires --uri parameter or else looks up sites/default/settings.php

In the documentation it is advised to create the aegir site as a 'normal' aegir site inside the /sites/ dir

During the Hostmaster installation wizard, one is required to run the Hosting Setup command for initial setup.

cd /var/aegir/drupal-6.13
/var/aegir/drush/drush.php hosting setup

If one has set up the aegir site to not be in sites/default/ but sites/aegir.example.com/, the current 'hosting setup' drush command fails with

Could not find a Drupal settings.php file at                         [error]
./sites/default/settings.php.

The command should be:

/var/aegir/drush/drush.php --uri=http://aegir.example.com hosting setup

so that it reads the correct settings.php

Patch attached fixes the instructions to include the --uri.

There was already this:

$uri =  HOSTING_DEFAULT_BASE_URL;

but this wasn't called anywhere and also wasn't defined, I define it using the global base_url parameter from bootstrap.inc