fix(engine): the database list creates a key in the config on save if not present (#411)

Description

Database list field was empty after config save and reload action via UI

Related issue

#411 (closed)

Examples

Checklist

• MR description has been reviewed
• MR changes are functionally tested
• MR does NOT have text changes OR there are text changes and they have been reviewed
• MR does NOT have API/CLI changes OR there are API/CLI changes and they have been reviewed
• MR does NOT have UI changes OR there are UI changes and they have been reviewed

Closes #411 (closed)