Update crypto-hashes-and-collisions.md

https://books.google.com/ngrams/graph?content=the+chance+is+extremely+little%2Cthe+chance+is+extremely+small&year_start=1800&year_end=2019&corpus=en-2019&smoothing=10&case_insensitive=true https://books.google.com/ngrams/graph?content=is+extremely+*&year_start=1800&year_end=2019&corpus=en-2019&smoothing=20&case_insensitive=true