fix test connect method in dao oracledb

Author: Artuomka

src/dal/dao/dao-oracledb.ts

@@ -588,7 +588,13 @@ export class DaoOracledb implements IDaoInterface {
   async testConnect(): Promise<ITestConnectResult> {
     const knex = this.configureKnex(this.connection);
     try {
-      const result = await knex('DUAL').select(1);
+      result = await knex
+      .transaction((trx) => {
+        knex.raw(`SELECT 1 FROM DUAL`).transacting(trx).then(trx.commit).catch(trx.rollback);
+      })
+      .catch((e) => {
+        throw new Error(e);
+      });
       if (result) {
         return {
           result: true,