network: Show the network dialogues after showing the shell

To avoid confusing the hell out of Mutter, we should show the
parented dialogue _after_ showing the parent itself.

https://bugzilla.gnome.org/show_bug.cgi?id=684927

panels/network/network-dialogs.c

@@ -233,7 +233,9 @@ show_wireless_dialog (CcNetworkPanel   *panel,
                                G_CALLBACK (wireless_dialog_response_cb),
                                closure, wireless_dialog_closure_closure_notify, 0);
 
-        gtk_widget_show (dialog);
+        g_object_bind_property (G_OBJECT (toplevel), "visible",
+                                G_OBJECT (dialog), "visible",
+                                G_BINDING_SYNC_CREATE);
 }
 
 void