Fix failure when running Non-System Apple Software Updates

[kenchan0130]

When using launchctl asuser with sudo, it's necessary to specify the username using the -u option.

The script does not pass the options correctly, so the softwareupdate command did not work correctly.

Fix #177

[Macjutsu]

I finally got around to testing this...

First sudo -i is correct for when there is no current user. It's essentially the same as sudo -u root... https://unix.stackexchange.com/questions/34670/is-there-a-difference-between-sudo-su-root-and-sudo-u-root-h-bin-bash

Second, in my testing, when a user is logged in, I can not confirm that sudo -u "${current_user_account_name}" works any better than sudo -i. (In other words, both methods work in my testing when a user is logged in.) However, if you claim that sudo -u "${current_user_account_name}" works better in your tests then I'll put it in the next beta release (with credit to you)... thanks!

Because I've already moved on to betas for super v4.1 I'm gonna close this request without a merge.