Ignore country when installing xorg for Ubuntu

I’m making a docker file for Ubuntu, and everything works for 14.04.

For 15.04 and 16.04, the build halts when installing xorg (need it for installing a driver) and asks for country of origin, I try to enter it but it does not continue.

How can I define the country of origin automatically, or ignore it? For apt-get install -y xorg