ssh: change the local copy of the ServerConfig passed to NewServerConn

Otherwise callers are forced to serialize access to the ServerConfig.

Change-Id: Id36f4d2877ea28b18447ef777d3839b21136c22f
Reviewed-on: https://go-review.googlesource.com/42821
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
1 file changed