Changing the QLineEdit 'country' to a QComboBox

see mail from Geert of 4th September 2014

"In verband met dat invulscherm: het veld ‘land’ kan best ook met
keuzemenu voorzien worden. (We zamelen in in België, Frankrijk en
Nederland)"

"As we only serve locations in the countries Belgium, France and The
Netherlands, you can change the QLineEdit into a QComboBox with these
limited options"