Workaround missing WM_TOUCH on mingw-w64 < 4.0

Upstream bug report: https://sourceforge.net/p/mingw-w64/bugs/460/

platform/windows/os_windows.cpp

@@ -63,12 +63,11 @@ __attribute__((visibility("default"))) DWORD NvOptimusEnablement = 0x00000001;
 #endif
 }
 
-#ifndef WM_MOUSEHWHEEL
-#define WM_MOUSEHWHEEL 0x020e
+// Workaround mingw-w64 < 4.0 bug
+#ifndef WM_TOUCH
+#define WM_TOUCH 576
 #endif
 
-//#define STDOUT_FILE
-
 extern HINSTANCE godot_hinstance;
 
 void RedirectIOToConsole() {