sysutils/gnome-control-center: Fix 40.0 build error

[00:01:39] ../panels/power/cc-power-panel.c:1748:58: error: use of undeclared identifier 'mobile_switch_changed_cb'
[00:01:39] gtk_widget_class_bind_template_callback (widget_class, mobile_switch_changed_cb);
[00:01:39] ^
[00:01:39] ../panels/power/cc-power-panel.c:1752:58: error: use of undeclared identifier 'wifi_switch_changed_cb'
[00:01:39] gtk_widget_class_bind_template_callback (widget_class, wifi_switch_changed_cb);
[00:01:39] ^
[00:01:39] 2 errors generated.

PR: 257662
Approved by: portmgr (implicit, fixing broken build)