Quick-enroll for OSX does not reload osqueryd

[javuto]

Overview

When enrolling a new OSX node (platform darwin) using the quick-enroll oneliner, if osqueryd is already running, the process is not stopped and there is the following error:

[+] Starting com.facebook.osqueryd
/Library/LaunchDaemons/com.facebook.osqueryd.plist: service already loaded

This seems because the current script uses unload instead of stop && unload for the launchd service.

Thanks @ewaher for finding this!