[docs] ctypes Module Documentation Bug

There's a long standing error in one of one examples in section 16.17.2.4 Function Prototypes <https://docs.python.org/3/library/ctypes.html?highlight=ctypes#function-prot...> of the documentation for the ctypes module. It's where there's an example demonstrating how to wrap the Windows MessageBoxA function. Please see stackoverflow.com question titled /The ctypes wraps “MessageBoxA” example didn't work in python33/ <http://stackoverflow.com/questions/18164994/the-ctypes-wraps-messageboxa-exa...> for more details and a possible fix. -- Martin