Get rid of VC2017 C++ compiler warning

[vSzemkel]

Type definitions for hook functions are a little bit inconsistent
Consider this to get rid ot the warning:

typedef int (WINAPI *TdefOldMessageBoxA)(HWND hWnd, LPCSTR lpText, LPCSTR lpCaption, UINT uType);
typedef int (WINAPI *TdefOldMessageBoxW)(HWND hWnd, LPWSTR lpText, LPCWSTR lpCaption, UINT uType);

int WINAPI NewMessageBoxA(HWND hWnd, LPCSTR lpText, LPCSTR lpCaption, UINT uType);
int WINAPI NewMessageBoxW(HWND hWnd, LPWSTR lpText, LPCWSTR lpCaption, UINT uType);