[Bugfix] Visual Studio needs stddef.h include to get size_t definition.


git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4305 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/config.h.cmake.in b/config.h.cmake.in
index 6b1ca3d..fef3649 100644
--- a/config.h.cmake.in
+++ b/config.h.cmake.in
@@ -7,5 +7,6 @@
 
 /* MS Visual Studio 2008 and newer doesn't know ssize_t */
 #if defined(HAVE_GNUTLS) && defined(WIN32) && !defined(__MINGW32__)
+#include <stddef.h>
 typedef size_t ssize_t;
 #endif