Add caveat about using percent in varargs example as per suggestion in bug #2106353

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@11743 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Examples/python/class/example.i

@@ -1,10 +1,4 @@
 /* File : example.i */
 %module example
 
-%{
-#include "example.h"
-%}
-
-/* Let's just grab the original header file here */
-%include "example.h"
-
+int printf(const char *fmt, ...);