Candidate build v6.16

Steps

1. Create two databases with sample and sample2
2. execute pg-sample.sql on both databases and rename some objects in sample2 database
3. Open schema diff
4. select source and target databases without selecting any schema
5. Click on compare
6. schema diff open with objects successfully
7. Now go into sample2 database and rename schema with public2
8. Now Click on compare again
9. schema diff open with objects successfully
10. Select all objects and click on generate script
11. query tool is on the wait state

Expected Result:
Generate script should be working if the user renames the schema and click on compare