Add message directing users to security guide
Addresses #2142, which was blocking on updates to zcash/support/security.html. That page has now been added, so this message directing users to the site can be included.
It displays in the zcash-cli --help and --version message text, and on the zcashd metrics screen.
Sorry for the churn on this, but the current message (introduced in #9073)
isn't acceptable:
$ src/bitcoin-cli getinfo
rpc: couldn't connect to server
(make sure server is running and you are connecting to the correct RPC port: -1 unknown)
Putting the error code after the words "RPC port" made me wonder whether
there was a port configuration issue.
This changes it to:
$ src/bitcoin-cli getinfo
error: couldn't connect to server: unknown (code -1)
(make sure server is running and you are connecting to the correct RPC port)
The two timeouts for the server and client, are essentially different:
- In the case of the server it should be a lower value to avoid clients
clogging up connection slots
- In the case of the client it should be a high value to accomedate slow
responses from the server, for example for slow queries or when the
lock is contended
Split the options into `-rpcservertimeout` and `-rpcclienttimeout` with
respective defaults of 30 and 900.
