Hi, I have the same problem and the above answer does not apply to the question actually.
If you add a "connection" by pressing the new button next to the "connection" drop down list somewhere in the center of the dialog, then the new connection once added cannot be deleted or edited. Even if you delete the configuration, when you add a new configuration that connection appears in the drop down and you cannot edit it or remove it from here or from any place I thought of looking.