Update to latest crypto library (again)

[fredo]

The crypto library used is most likely outdated. We need to update it to the latest changes so that it complies with Gnosis Chain.

[jannikluhn]

Issues that will go into the next shcrypto release:

• https://github.com/shutter-network/shutter/issues/118
• https://github.com/shutter-network/shutter/issues/119
• https://github.com/shutter-network/shutter/issues/120