Revert "Disable desktop settings awareness for now"

This reverts commit 10652f8dd675aa0d12c11597c165831c8ba0b8b4 which
disabled desktop settings awareness to avoid loading themes for X11.

However, Hawaii is a Wayland-only desktop environment and only the
themes shipped with Qt are provided by Maui. Disabling desktop
settings awareness will not load icon themes making the DE unusable.