For pkexec based apps under wayland need to pass wayland details

[fossfreedom]

Where we have used "pkexec" in the code we need to supplement something like the following to allow the app to run successfully under wayland

pkexec env WAYLAND_DISPLAY="$XDG_RUNTIME_DIR/$WAYLAND_DISPLAY"  XDG_RUNTIME_DIR=/user/run/0  lightdm-settings

e.g.

pkexec env WAYLAND_DISPLAY="$XDG_RUNTIME_DIR/$WAYLAND_DISPLAY"  XDG_RUNTIME_DIR=/user/run/0  lightdm-settings