fix(dal) Fix wrong schema version, in constants

fix(dal): not need to create txs indices in the migration script (already done in SqliteTransactions.ts)

app/lib/constants.ts

@@ -218,7 +218,7 @@ module.exports = {
 
   PEER: CommonConstants.PEER,
 
-  CURRENT_DB_VERSION: 27, // Should be set with 'max(keys(MetaDAL.migration)) + 1'
+  CURRENT_DB_VERSION: 28, // Should be set with 'max(keys(MetaDAL.migration)) + 1'
 
   NETWORK: {
     MAX_MEMBERS_TO_FORWARD_TO_FOR_SELF_DOCUMENTS: 10,

app/lib/dal/sqliteDAL/MetaDAL.ts

@@ -195,9 +195,7 @@ export class MetaDAL extends AbstractSQLite<DBMeta> {
     25: async () => {},
 
     // Drop old table 'txs' (replaced by a file 'txs.db')
-    26: async () => {
-      await this.exec("BEGIN;" + "DROP TABLE IF EXISTS txs;" + "COMMIT;");
-    },
+    26: "BEGIN;" + "DROP TABLE IF EXISTS txs;" + "COMMIT;",
 
     // Add columns 'issuer' and 'recipient' in transaction table - see issue #1442
     27: async () => {
@@ -215,8 +213,6 @@ export class MetaDAL extends AbstractSQLite<DBMeta> {
           "DROP INDEX IF EXISTS idx_txs_received;" +
           "DROP INDEX IF EXISTS idx_txs_output_base;" +
           "DROP INDEX IF EXISTS idx_txs_output_amount;" +
-          "CREATE INDEX IF NOT EXISTS idx_txs_issuers ON txs (issuers);" +
-          "CREATE INDEX IF NOT EXISTS idx_txs_recipients ON txs (recipients);" +
           "COMMIT;"
       );