Update the Winsock API version requested by libpq.

Update the Winsock API version requested by libpq.

According to Microsoft's documentation, 2.2 has been the current
version since Windows 98 or so.  Moreover, that's what the Postgres
backend has been requesting since 2004 (cf commit 4cdf51e64).
So there seems no reason for libpq to keep asking for 1.1.

Bring thread_test along, too, so that we're uniformly asking for 2.2
in all our WSAStartup calls.

It's not clear whether there's any point in back-patching this,
so for now I didn't.

Discussion: https://postgr.es/m/132799.1602960277@sss.pgh.pa.us