Minor fix for Web Cam on OpenCV 3.x

AlexeyAB

2018-04-06 1b1221ace5f49b5b464cf7f4ff89f31cf03d3da1

 src/rnn_layer.h

@@ -5,6 +5,7 @@
#include "activations.h"
#include "layer.h"
#include "network.h"
#define USET

layer make_rnn_layer(int batch, int inputs, int hidden, int outputs, int steps, ACTIVATION activation, int batch_normalize, int log);