Minor fix for Web Cam on OpenCV 3.x

AlexeyAB

2018-04-06 1b1221ace5f49b5b464cf7f4ff89f31cf03d3da1

 src/avgpool_layer.h

@@ -2,9 +2,9 @@
#define AVGPOOL_LAYER_H

#include "image.h"
#include "params.h"
#include "cuda.h"
#include "layer.h"
#include "network.h"

typedef layer avgpool_layer;