Fix build of dlls/winhttp/request.c (on non-Linux)

[Gerald Pfeifer]

I wouldn't be surprised for Darwin to be broken as well right now,
though my personal encounter has been on FreeBSD 6.3.  Luckily, an
easy one. ;-)

Gerald

ChangeLog:
#include <sys/socket.h>.

Index: dlls/winhttp/request.c
===================================================================
RCS file: /home/wine/wine/dlls/winhttp/request.c,v
retrieving revision 1.11
diff -u -3 -p -r1.11 request.c
--- dlls/winhttp/request.c	27 Aug 2008 13:25:47 -0000	1.11
+++ dlls/winhttp/request.c	28 Aug 2008 18:35:49 -0000
@@ -24,6 +24,9 @@
 #ifdef HAVE_ARPA_INET_H
 # include <arpa/inet.h>
 #endif
+#ifdef HAVE_SYS_SOCKET_H
+# include <sys/socket.h>
+#endif
 
 #include "windef.h"
 #include "winbase.h"