CnP/Wayland: Fix window check for Wayland invocations.
CnP/Wayland: Fix window check for Wayland invocations.

This was leading to never enter the cnp functions dedicated to Wayland,
as the given object was not a window. The Copy And Paste test was not
working for this reason.

FlorentRevest/Elementary,rvandegrift/elementary,tasn/elementary,FlorentRevest/Elementary,tasn/elementary,tasn/elementary,tasn/elementary,FlorentRevest/Elementary,FlorentRevest/Elementary,rvandegrift/elementary,tasn/elementary,rvandegrift/elementary,rvandegrift/elementary