md5 too slow

[h2oiswater]

Thanks for your work, I had backup my wechat files using your script, but it will stuck quite long when file too large, so I replaced md5 to MurmurHash, same result but faster.

import mmh3

def return_murmurhash(file):
    hash_value = mmh3.hash(file)
    return hash_value

pip install mmh3

[h2oiswater]

I can submit a PR if you agree :)

[Cristina269]

I can submit a PR if you agree :)

Thanks for your suggestion! I didn't consider the speed issue when writing the script because I don't have too many large files... Thank you. Please feel free to submit a PR with your proposed changes.

[Cristina269]

I can submit a PR if you agree :)

I submitted new code to make it more readable.