Win32: fixed build with Visual Studio 2005 Express.

It is available via winetricks which makes it still usable, and has
an old crtdefs.h which uses _CRT_SECURE_NO_DEPRECATE instead of
_CRT_SECURE_NO_WARNINGS to suppress warnings.

Reported by HAYASHI Kentaro,
http://mailman.nginx.org/pipermail/nginx-devel/2012-August/002542.html

src/os/win32/ngx_win32_config.h

@@ -18,6 +18,7 @@
 
 /* enable getenv() and gmtime() in msvc8 */
 #define _CRT_SECURE_NO_WARNINGS
+#define _CRT_SECURE_NO_DEPRECATE
 
 /*
  * we need to include <windows.h> explicitly before <winsock2.h> because