Don't set SO_SNDBUF on recent Windows versions that have a bigger default.

Don't set SO_SNDBUF on recent Windows versions that have a bigger default.

It's unnecessary to set it if the default is higher in the first place.
Furthermore, setting SO_SNDBUF disables the so-called "dynamic send
buffering" feature, which hurts performance further. This can be seen
especially when the network between the client and the server has high
latency.

Chen Huajun