message: dnn: fix some tutorial links
diff: @@ -13,7 +13,7 @@ We will demonstrate results of this example on the following picture.
  Source Code
  -----------
  -We will be using snippets from the example application, that can be downloaded [here](https://github.com/opencv/opencv/blob/master/modules/samples/dnn/caffe_googlenet.cpp).
  +We will be using snippets from the example application, that can be downloaded [here](https://github.com/opencv/opencv/blob/master/samples/dnn/caffe_googlenet.cpp).
  @include dnn/caffe_googlenet.cpp
  @@ -21,11 +21,11 @@ Explanation
  -----------
  -# Firstly, download GoogLeNet model files:
  - [bvlc_googlenet.prototxt ](https://raw.githubusercontent.com/opencv/opencv/master/modules/samples/data/dnn/bvlc_googlenet.prototxt) and
  + [bvlc_googlenet.prototxt ](https://raw.githubusercontent.com/opencv/opencv/master/samples/data/dnn/bvlc_googlenet.prototxt) and
  [bvlc_googlenet.caffemodel](http://dl.caffe.berkeleyvision.org/bvlc_googlenet.caffemodel)
  Also you need file with names of [ILSVRC2012](http://image-net.org/challenges/LSVRC/2012/browse-synsets) classes:
  - [synset_words.txt](https://raw.githubusercontent.com/opencv/opencv/master/modules/samples/data/dnn/synset_words.txt).
  + [synset_words.txt](https://raw.githubusercontent.com/opencv/opencv/master/samples/data/dnn/synset_words.txt).
  Put these files into working dir of this program example.
  