FIX to work with RELEASE compilation

src/sensors/usb_cam/usb_cam_load_yaml.cpp

@@ -35,7 +35,7 @@ static ParamsBasePtr createParamsUSBCAMSensor(const std::string & _filename_dot_
 }
 
 // Register in the SensorFactory
-const bool registered_usbcam_params = ParamsFactory::get().registerCreator("USB_CAM", createParamsUSBCAMSensor);
+const bool VU_UNUSED registered_usbcam_params = ParamsFactory::get().registerCreator("USB_CAM", createParamsUSBCAMSensor);
 
 } /* namespace [unnamed] */