Better error message requested when a client's security certificates are outdated. #6613
Description
Describe the problem
I have a couple of older machines keep saying they can't connect to Einstein and Asteroids. The error message in Boinc was precisely the same as when the server is down. I ignored it. Until someone in Einstein suggested my computers may be out of date with certificates. They were. One is an older unsupported version of Windows, and the other had a windows update service corruption.
Describe the solution you'd like
Please add a more useful error message in Boinc so the user knows they need to fix their certificates.
Additional context
No response