Add winsock library (ws2_32.lib) to multi-threaded xpdev props file

This additional library was already included in the single-threaded version, so this was just a miss.
14 jobs for dailybuild_win32 in 9 minutes and 37 seconds (queued for 12 seconds)
Status Job ID Name Coverage
  Build
passed #34843
FreeBSD
jsdoor-freebsd

00:03:56

passed #34844
Linux
jsdoor-linux

00:06:23

passed #34846
FreeBSD
jsdoor-windows

00:01:56

passed #34838
FreeBSD
sbbs-freebsd

00:05:27

passed #34833
Linux
sbbs-linux

00:09:31

passed #34836
Windows
sbbs-windows

00:05:04

passed #34845
FreeBSD
sexpots-freebsd

00:00:17

passed #34834
Linux
sexpots-linux

00:00:20

passed #34837
Windows
sexpots-windows

00:00:28

passed #34841
FreeBSD
syncdraw-freebsd

00:00:28

passed #34842
Linux
syncdraw-linux

00:00:58

passed #34839
FreeBSD
syncterm-freebsd

00:01:03

passed #34835
Linux
syncterm-linux

00:02:47

passed #34840
FreeBSD
syncterm-windows

00:01:46