Press Alt + F2 and paste software-properties-gtk
(or you can open "Software Center" then go to "Edit" > "Software Sources"). Go to tab "Other Software", choose the duplicate entry and press the "Remove" button.
Press Alt + F2 and paste software-properties-gtk
(or you can open "Software Center" then go to "Edit" > "Software Sources"). Go to tab "Other Software", choose the duplicate entry and press the "Remove" button.