ownership proof does not commit to round parameters

[nothingmuch]

the round id is comitted to by the ownership proof, but it is not a hash of the parameters, and instead is just a uuid

blindjoin/client/src/round/mod.rs

Line 7 in 982fc28

pub round_id: uuid::Uuid,

if it was a cryptographic hash of the parameters and re-computed from the parameters by clients this would ensure that the RSA blind signing key is bound to the round identity, mitigating key based tagging