pgsql: Reverse inclusion order of <ws2tcpip.h> and <winsock2.h>, per

Log Message:
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Reverse inclusion order of <ws2tcpip.h> and <winsock2.h>, per Dave Page.

Modified Files:
--------------
pgsql/src/include/port/win32/sys:
socket.h (r1.4 -> r1.5)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/port/win32/sys/socket.h.diff?r1=1.4&amp;r2=1.5)