FR: MSC to warn on broken certificates

[llauren]

The Managedsoftwareupdate app should warn if there is a certificate problem like the command line version does. Now the app behaves like there is no problem but it can't get updates or install software.

Backstory: I managed to send out a profile which removed the certificate needed to access our munki server (ouch). This resulted in people not being able to get the updated profile that would restore the certificate, because it wouldn't appear in the MSC app. There was also no error message indicating that there was a problem.

I know the MSC app likes to hide the technicalities from unprepared users, but in the name of transparency, i don't think an app should behave like everything's alright when it can't function.