Apply header guard check

include/Nazara/Widgets/DebugOff.hpp

@@ -2,6 +2,8 @@
 // This file is part of the "Nazara Engine - Widgets module"
 // For conditions of distribution and use, see copyright notice in Config.hpp
 
+// no header guards
+
 // We assume that Debug.hpp has already been included, same thing for Config.hpp
 #if NAZARA_WIDGETS_MANAGE_MEMORY
 	#undef delete