fix racktables Apache setup

use apache::site to put the file in
sites-available and create the symlink

this was broken with:

Role::Racktables/File[/etc/apache2/sites-enabled/racktables.wikimedia.org]:
Ensure set to :present but file type is link so no content will be synced

so can't install changes at the moment

Change-Id: If44105e4f63b5162a40f424a81b88761524ff0ae
Merge "fix racktables Apache setup" into production