Add datatype for is_spent sqlite column

Although, Sqlite column accepts
values of any type, it is
important to annotate this column
to make it easy to reason about.

Author: vladimirfomene

src/database/sqlite.rs

@@ -43,6 +43,10 @@ static MIGRATIONS: &[&str] = &[
     "INSERT INTO transaction_details SELECT txid, timestamp, received, sent, fee, height FROM transaction_details_old;",
     "DROP TABLE transaction_details_old;",
     "ALTER TABLE utxos ADD COLUMN is_spent;",
+    "ALTER TABLE utxos RENAME TO utxos_old;",
+    "CREATE TABLE utxos (value INTEGER, keychain TEXT, vout INTEGER, txid BLOB, script BLOB, is_spent BOOLEAN DEFAULT 0);",
+    "INSERT INTO utxos SELECT value, keychain, vout, txid, script, is_spent FROM utxos_old;",
+    "DROP TABLE utxos_old;",
     // drop all data due to possible inconsistencies with duplicate utxos, re-sync required
     "DELETE FROM checksums;",
     "DELETE FROM last_derivation_indices;",
@@ -51,7 +55,6 @@ static MIGRATIONS: &[&str] = &[
     "DELETE FROM transaction_details;",
     "DELETE FROM transactions;",
     "DELETE FROM utxos;",
-    "DROP INDEX idx_txid_vout;",
     "CREATE UNIQUE INDEX idx_utxos_txid_vout ON utxos(txid, vout);"
 ];