Description of problem:
This crash happens when switching "sharing" off with gnome-users-share not installed.

Version-Release number of selected component:
control-center-3.17.90-1.fc23

Additional info:
reporter:       libreport-2.6.2
backtrace_rating: 4
cmdline:        gnome-control-center --overview
crash_function: _gtk_builder_get_widget
executable:     /usr/bin/gnome-control-center
kernel:         4.2.0-1.fc23.x86_64
runlevel:       N 5
type:           CCpp

Truncated backtrace:
Thread no. 1 (10 frames)
 #4 _gtk_builder_get_widget at cc-sharing-panel.c:56
 #5 cc_sharing_panel_master_switch_notify at cc-sharing-panel.c:109
 #11 g_object_notify_by_spec_internal at gobject.c:1155
 #12 g_object_notify_by_pspec at gobject.c:1265
 #13 gtk_switch_set_active at gtkswitch.c:1097
 #14 gtk_switch_begin_toggle_animation at gtkswitch.c:195
 #15 ffi_call_unix64 at ../src/x86/unix64.S:76
 #16 ffi_call at ../src/x86/ffi64.c:525
 #17 g_cclosure_marshal_generic_va at gclosure.c:1594
 #18 _g_closure_invoke_va at gclosure.c:864