RenderWindowTest: Fix test failure in ::SetIcon
RenderWindowTest: Fix test failure in ::SetIcon

* Adding nom::init call in our main function resolves the issue; the
failures occurred only when the executable was ran from a working path
(i.e.: shell) that differed from the executable's working dir; leaving
the test unable to locate its icon.png file!

i8degrees/nomlib,i8degrees/nomlib,i8degrees/nomlib,i8degrees/nomlib