Use g_autoptr to release schema reference

Author: jpnurmi

shell/platform/linux/fl_settings_plugin.cc

@@ -101,7 +101,7 @@ static void update_settings(FlSettingsPlugin* self) {
         g_settings_get_string(self->interface_settings, kDesktopClockFormatKey);
     always_use_24hr = g_strcmp0(clock_format, kClockFormat24Hour) == 0;
 
-    GSettingsSchema* schema = nullptr;
+    g_autoptr(GSettingsSchema) schema = nullptr;
     g_object_get(self->interface_settings, "settings-schema", &schema, nullptr);
     if (g_settings_schema_has_key(schema, kDesktopColorSchemeKey)) {
       g_autofree gchar* color_scheme = g_settings_get_string(