Qt CI builder Linux Ubuntu_16_04 (gcc-x86_64) doesn't support EGL Wayland

Trying to add a unit test that relies on Wayland EGL fails https://codereview.qt-project.org/#/c/210552/ on one of the Linux server.

Running the Qt examples also fails:

<johanhelsing> the compositor prints: "libEGL warning: bad surface attribute 0x3080" when a client connects

<johanhelsing> I tried with pure-qml as well, there I also get the same, plus: "failed to create eglsurface <number> <number>" and "failed to bind"