Bug#802674: im-config: requiring GSettings change for setting GTK IMModule

[Aron Xu]

Package: src:im-config

In recent versions of GNOME/Gtk, a GSettings change is needed for
setting GTK IMModules, for example:

$ gsettings set org.gnome.settings-daemon.plugins.xsettings overrides
"{'Gtk/IMModule':<'fcitx'>}"

This leads to a little trouble for im-config for setting input methods
for users.

Thanks,
Aron