don't need to test _WINDOWS if only being used on Windows

src/NativeWrappers/Common/WindowsDLL.cpp

@@ -1,10 +1,8 @@
-#ifdef _WINDOWS
+#ifndef VC_EXTRALEAN
-	#ifndef VC_EXTRALEAN
+	#define VC_EXTRALEAN
-		#define VC_EXTRALEAN
-	#endif
-	#include "windows.h"
-	
-	BOOL APIENTRY DllMain( HANDLE, DWORD, LPVOID ){
-		return TRUE;
-	}
 #endif
+#include "windows.h"
+	
+BOOL APIENTRY DllMain( HANDLE, DWORD, LPVOID ){
+	return TRUE;
+}