Fix for multi-GPU and DGX

AlexeyAB

2018-06-03 483fdfa951feeb20903da1598cb9d611b93de6ca

Fix for multi-GPU and DGX

 src/detector.c

@@ -106,7 +106,7 @@
    args.hue = net.hue;

#ifdef OPENCV
    args.threads = 3;
    args.threads = 3 * ngpus;
    IplImage* img = NULL;
    float max_img_loss = 5;
    int number_of_lines = 100;