Set delayedPayoutTxBytes when setting delayedPayoutTx

Fixes bisq-network#3473

The delayedPayoutTx is not committed to the wallet as long it is not
published. The seller who creates the delayedPayoutTx has not stored the
delayedPayoutTxBytes which caused a nullpointer after restart.

core/src/main/java/bisq/core/trade/Trade.java

@@ -666,6 +666,7 @@ public Transaction getDepositTx() {
 
     public void applyDelayedPayoutTx(Transaction delayedPayoutTx) {
         this.delayedPayoutTx = delayedPayoutTx;
+        this.delayedPayoutTxBytes = delayedPayoutTx.bitcoinSerialize();
         persist();
     }