dao-exec: temporary workaround, but serial and blind should be that used in coin 0

bin/drk/src/rpc_dao.rs

@@ -455,8 +455,8 @@ impl Drk {
                 value: proposal.amount,
                 token_id: proposal.token_id,
                 public: proposal.recipient,
-                serial: user_serial,
-                coin_blind: user_coin_blind,
+                serial: proposal.serial,
+                coin_blind: proposal.bulla_blind,
                 spend_hook: pallas::Base::zero(),
                 user_data: pallas::Base::zero(),
             },