NPE when adding connection with invalid URL

If I enter total nonsense into url (like 'abc' '123'), the wizard dialogs stays open even though creating the connection failed. The dialog may be closed by hitting cancel. No error is displayed, but a NPE is in the log.

There is one little issue related to this one.
If I enter 'http://something' dialog gets closed and is treated like valid but not reachable connection. This is fine
But if I enter 'http:/something' behavior is same, which is wrong, There is a need to fix regex determining valid or invalid URL.