gnome-shell-client: make async by default

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
updates for gnome-shell-client changes

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>
Merge branch 'wip/async-dbus'

* wip/async-dbus:
  updates for gnome-shell-client changes
  gnome-shell-client: make async by default