David Fifield 23759e203f Apply a timeout to upstream dials in the server. ...

In my testing locally, these dials would time out after about 30 seconds
anyway:
	2021/04/20 23:26:46 begin session 54cafb53
	2021/04/20 23:26:47 begin stream 54cafb53:3
	2021/04/20 23:27:19 stream 54cafb53:3 handleStream: stream 54cafb53:3 connect upstream: dial tcp X.X.X.X:YYYY: connect: connection timed out
	2021/04/20 23:27:19 end stream 54cafb53:3
Which is in line with the documentation for net.Dialer:
	https://golang.org/pkg/net/#Dialer
	With or without a timeout, the operating system may impose its
	own earlier timeout. For instance, TCP timeouts are often around
	3 minutes.
But may as well be explicit.

This commit has the side effect of changing the error message from
"connection timed out" to "i/o timeout".
	2021/04/20 23:28:08 begin session 05b0a46e
	2021/04/20 23:28:09 begin stream 05b0a46e:3
	2021/04/20 23:28:39 stream 05b0a46e:3 handleStream: stream 05b0a46e:3 connect upstream: dial tcp X.X.X.X:YYYY: i/o timeout
	2021/04/20 23:28:39 end stream 05b0a46e:3

2021-04-20 17:32:15 -06:00

..

main.go

Apply a timeout to upstream dials in the server.

2021-04-20 17:32:15 -06:00