[Server] Leaked authentication server sockets

[jonnyhyman]

In spooky circumstances, the server app sometimes keeps authentication server sockets open even after closing the app. This is because the forked python processes are not killed properly. This seems to happen mostly after a crash of the server app

If this occurs, go to Activity Monitor/Task Manager, and quit any of the remaining processes manually, (they will be python processes) then start the server again

A deeper fix will be to provide a cleaner crash handling (upon unhandled exception, we should close all authentication sockets and then quit the app!)