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The crypto library used is most likely outdated.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:

• Replace BLS library in shcrypto with BLST shutter#118
• Update Hash1 to use standard hash-to-curve function shutter#119
• Update encrypted message version prefix shutter#120