show at least some signal in serverRage
Summary:
I'm looking at bug reports which have "rage" like this:
```
LSP belief of hh_server_state:
[12:28:52.263] [21.888s ago] hh_server ready
[12:28:52.258] [21.893s ago] hh_server typechecking (local)
[12:22:06.356] [427.794s ago] hh_server ready
LSP adapter state: Main_loop
PSTACK
1398850 (main) -
PSTACK
1398611 (monitor) -
```
From this I don't have a read on whether hh_server really truly is alive and responding. Also, the server and monitor logs show a snapshot but still don't tell me if hh_server is alive and responding.
This diff makes hh_server at least contributes something to the log.
(Unrelated: the pstack entries are all empty. I tried at the command-line... pstack truly does give empty output for hh_server at the moment while giving non-empty output for hh_client. Not sure why).
Reviewed By: 2BitSalute
Differential Revision:
D16287543
fbshipit-source-id:
54408ba8a9302473e7c6a2ddcb154d0606a7d3b4