Missing inputs to Fiat-Shamir hash (in non_threshold)

[maurges]

In line 200 of non_threshold.rs, both X_i and sch_commit should be included in the hash.

Of course, line 222 also needs to be fixed so verification works

X_i is included, it's just called Xs (for the fact that it's many exes)

Moved from https://github.com/dfns-labs/paillier-zk/issues/28

[maurges]

sch_commits are also included as As. I can't find B_i though

[maurges]

Oh crap, it's completely gone with the schnorr proof as well

[maurges]

Right, it's for el-gamal keys which we don't have. Ok