[gnome-tweak-tool/gnome-3-24] keymouse: Only show Overview Shortcut if GNOME Shell is running

[Jeremy Bicha <jbicha src gnome org>]

commit a08d3c1d8d1eba4be4edb169eeb741cfa22ac634
Author: Jeremy Bicha <jbicha ubuntu com>
Date:   Sun Jun 11 19:56:47 2017 -0400

    keymouse: Only show Overview Shortcut if GNOME Shell is running

 gtweak/tweaks/tweak_group_keymouse.py |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/gtweak/tweaks/tweak_group_keymouse.py b/gtweak/tweaks/tweak_group_keymouse.py
index 8e939ed..69c4b7e 100644
--- a/gtweak/tweaks/tweak_group_keymouse.py
+++ b/gtweak/tweaks/tweak_group_keymouse.py
@@ -20,9 +20,13 @@ import os.path
 from gi.repository import GLib
 
 import gtweak
+from gtweak.gshellwrapper import GnomeShellFactory
 from gtweak.utils import XSettingsOverrides, walk_directories, make_combo_list_with_default
 from gtweak.widgets import ListBoxTweakGroup, GSettingsComboTweak, GSettingsSwitchTweak, 
GetterSetterSwitchTweak, Title, GSettingsComboEnumTweak
 
+_shell = GnomeShellFactory().get_shell()
+_shell_loaded = _shell is not None
+
 class KeyThemeSwitcher(GSettingsComboTweak):
     def __init__(self, **options):
         GSettingsComboTweak.__init__(self,
@@ -55,7 +59,7 @@ TWEAK_GROUPS = [
         GSettingsComboTweak(_("Switch between overview and desktop"),
                               "org.gnome.mutter",
                               "overlay-key",
-                              [("Super_L", _("Left super")), ("Super_R", _("Right super"))]),
+                              [("Super_L", _("Left super")), ("Super_R", _("Right super"))], 
loaded=_shell_loaded),
               
         Title(_("Mouse"), ""),
         GSettingsComboEnumTweak(_("Acceleration profile"),