Fix broken link in tutorials.md (#2302)

Fix broken link in `tutorials.md`

tutorials.md

@@ -39,7 +39,7 @@
 * [Colouring words by topic in a document, print words in a topics](https://github.com/RaRe-Technologies/gensim/blob/develop/docs/notebooks/topic_methods.ipynb)
 * [Topic Coherence, a metric that correlates that human judgement on topic quality.](https://github.com/RaRe-Technologies/gensim/blob/develop/docs/notebooks/topic_coherence_tutorial.ipynb)
 * [Compare topics and documents using Jaccard, Kullback-Leibler and Hellinger similarities](https://github.com/RaRe-Technologies/gensim/blob/develop/docs/notebooks/distance_metrics.ipynb)
-* [America's Next Topic Model slides](https://speakerdeck.com/tmylk/americas-next-topic-model?slide=6) -- How to choose your next topic model, presented at Pydata London 5 July 2016 by Lev Konstantinovsky
+* [America's Next Topic Model slides](https://speakerdeck.com/tmylk/americas-next-topic-model-at-pydata-berlin-august-2016?slide=7) -- How to choose your next topic model, presented at Pydata Berlin 10 August 2016 by Lev Konstantinovsky
 * [Classification of News Articles using Topic Modeling](https://github.com/RaRe-Technologies/gensim/blob/develop/docs/notebooks/gensim_news_classification.ipynb)
 * [LDA: pre-processing and training tips](https://github.com/RaRe-Technologies/gensim/blob/develop/docs/notebooks/lda_training_tips.ipynb)