There's a handy mod for that, courtesy of @wondible Of course, it will only work if server.exe is still running (which might not be always the case)
Observationally, if you quit PA, it closes down any servers it started. If the client crashes, the server stays running. Sometimes it stays running and borked, so I have to use 'killall server' to be able to play again.
As guys said you can only do that if server still running. Though you don't really need a mod to reconnect to local game because you can do that by going to "Single Player -> AI Skirmish" again.
