Changed "awesome-cryptography" link (sindresorhus#740)

readme.md

@@ -219,7 +219,7 @@ Check out my [blog](https://blog.sindresorhus.com) and follow me on [Twitter](ht
 - [Speech and Natural Language Processing](https://github.com/edobashira/speech-language-processing)
 	- [Spanish](https://github.com/dav009/awesome-spanish-nlp)
 - [Linguistics](https://github.com/theimpossibleastronaut/awesome-linguistics)
-- [Cryptography](https://github.com/MaciejCzyzewski/retter)
+- [Cryptography](https://github.com/sobolevn/awesome-cryptography)
 - [Computer Vision](https://github.com/jbhuang0604/awesome-computer-vision)
 - [Deep Learning](https://github.com/ChristosChristofidis/awesome-deep-learning) - Neural networks.
 	- [TensorFlow](https://github.com/jtoy/awesome-tensorflow)