message: Minor code simplification.
diff: @@ -400,9 +400,10 @@ impl ProverCommandExecutor {
  let out_cred_id = cred_id.map(String::from).unwrap_or(uuid::Uuid::new_v4().to_string());
  let catpol_json = self.get_credential_attr_tag_policy(wallet_handle, credential.cred_def_id.as_str())?;
  - let catpol: Option<CredentialAttrTagPolicy> = match catpol_json {
  - _ if catpol_json == "null" => None,
  - _ => Some(serde_json::from_str(catpol_json.as_str()).to_indy(IndyErrorKind::InvalidState, "Cannot deserialize CredentialAttrTagPolicy")?)
  + let catpol: Option<CredentialAttrTagPolicy> = if catpol_json.ne("null") {
  + Some(serde_json::from_str(catpol_json.as_str()).to_indy(IndyErrorKind::InvalidState, "Cannot deserialize CredentialAttrTagPolicy")?)
  + } else {
  + None
  };
  let cred_tags = self.anoncreds_service.prover.build_credential_tags(&credential, &catpol.as_ref());
  