Updating Meson build Wayland conditional to match Makefile
The conditional logic is flawed.
If HAVE_WAYLAND is true, only then should the path be updated to include wayland-sessions.
Test Plan: Verified desired output in build/meson-info/intro-installed.json after testing a clean build
Subscribers: cedric, zmike
Differential Revision: https://phab.enlightenment.org/D9868