provision-verify attempts to run apache2ctl on a nginx install

Hi!

I have followed the latest Manual Installation guide carefully to install Aegir with Nginx on a clean server.

I ended up receiving the `[sudo] password for aegir:` prompt after submitting the following command:

hostmaster-install aegir.het.lolma.us --http_service_type="nginx" --client_email="lolmaus@gmail.com" --debug

and typing the mysql root password.

Here's the full output with the --debug parameter: https://gist.github.com/4563424

The last message is:

Running: /usr/share/drush/drush.php  @server_master provision-verify --backend  2>&1 [15.51 sec, 9.83 MB]                [command]
[sudo] password for aegir:

I've set sudoers to allow every command for Aegir and ran provision-verify manually. I've found out that it attempts to execute apachectl:

DRUSH_BACKEND_OUTPUT_START>>>{"output":"Executing: ln -sf '\/var\/aegir\/config\/server_master\/nginx.conf' '\/var\/aegir\/config\/nginx.conf'\nExecuting: sudo \/usr\/sbin\/apachectl graceful\n sudo: \/usr\/sbin\/apachectl: command not found\n","object":[],"error_status":0,"log":[{...

This prevents me from installing Aegir, so marking this as major. Please help.