MinGW tweak: Only define RFB_HAVE_SENDINPUT is we have MOUSEEVENTF_VIRTUALDESK.

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@3335 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/win/rfb_win32/SInput.cxx b/win/rfb_win32/SInput.cxx
index db59287..a8e6941 100644
--- a/win/rfb_win32/SInput.cxx
+++ b/win/rfb_win32/SInput.cxx
@@ -36,7 +36,7 @@
 #include <rdr/Exception.h>
 #include <rfb/LogWriter.h>
 
-#if(defined(INPUT_MOUSE) && defined(RFB_HAVE_MONITORINFO))
+#if(defined(INPUT_MOUSE) && defined(RFB_HAVE_MONITORINFO) && defined(MOUSEEVENTF_VIRTUALDESK))
 #define RFB_HAVE_SENDINPUT
 #else
 #pragma message("  NOTE: Not building SendInput support.")