Update guid.cpp

Author: Gogoshika-ga

source/dependencies/crossguid/guid.cpp

@@ -22,7 +22,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 */
 
-#include <string.h>
+#include <cstring>
 #include "guid.h"
 
 #ifdef GUID_LIBUUID