sweep: Remove publishing last-tx logic.

We remove the publishing of the last published sweep tx during the
startup of the sweeper. This republishing can lead to situations
where funds of the default wallet might be locked for neutrino
backend clients.
Moreover all related tests are removed as well.

sweep/store_test.go

@@ -42,15 +42,6 @@ func testStore(t *testing.T, createStore func() (SweeperStore, error)) {
 		t.Fatal(err)
 	}
 
-	// Initially we expect the store not to have a last published tx.
-	retrievedTx, err := store.GetLastPublishedTx()
-	if err != nil {
-		t.Fatal(err)
-	}
-	if retrievedTx != nil {
-		t.Fatal("expected no last published tx")
-	}
-
 	// Notify publication of tx1
 	tx1 := wire.MsgTx{}
 	tx1.AddTxIn(&wire.TxIn{
@@ -83,16 +74,6 @@ func testStore(t *testing.T, createStore func() (SweeperStore, error)) {
 		t.Fatal(err)
 	}
 
-	// Assert that last published tx2 is present.
-	retrievedTx, err = store.GetLastPublishedTx()
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if tx2.TxHash() != retrievedTx.TxHash() {
-		t.Fatal("txes do not match")
-	}
-
 	// Assert that both txes are recognized as our own.
 	ours, err := store.IsOurTx(tx1.TxHash())
 	if err != nil {