Method Invalidate

src/GCodes/GCodeFileInfo.h:26–26

		ThumbnailInfo() noexcept : width(0), format(ImageFormat::png) { }
		bool IsValid() const noexcept { return width != 0; }
		void Invalidate() noexcept { width = 0; }
	};

	GCodeFileInfo() noexcept { Init(); }