terminal: don't get 'word-chars' from org.gnome.Terminal.Legacy.Profile

(gedit:4931): GLib-GIO-ERROR **: Settings schema 'org.gnome.Terminal.Legacy.Profile' does not contain a key named 'word-chars'
Regression after https://git.gnome.org/browse/gnome-terminal/commit?id=e63cbcf64d2fde5bc4a8cb8ae0e3ef8c95a6d889

Reference: https://bugzilla.gnome.org/show_bug.cgi?id=732422
Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>