When user adds new datasource, there is a possibility to test connection to datasource before the wizard is closed.

Expected behavior (this is same as when user cancels wizard):

• user tests connection
• datasource is created on background
• user closes wizard by clicking on cross in top right corner
• datasource is removed after server reload

Current behavior:

• user tests connection
• datasource is created on background
• user closes wizard by clicking on cross in top right corner
• datasource remains in model after server reload