remove unwrap in signer state machine

src/state_machine/signer/mod.rs

@@ -387,7 +387,7 @@ impl<SignerType: SignerTrait> Signer<SignerType> {
         let mut missing_public_shares = HashSet::new();
         let mut missing_private_shares = HashSet::new();
         let mut bad_public_shares = HashSet::new();
-        let threshold: usize = self.threshold.try_into().unwrap();
+        let threshold: usize = self.threshold.try_into()?;
         if let Some(dkg_end_begin) = &self.dkg_end_begin_msg {
             for signer_id in &dkg_end_begin.signer_ids {
                 if let Some(shares) = self.dkg_public_shares.get(signer_id) {