update E_Client->desk member upon focusing a sticky client

a sticky window previously would always have the desk set for where
it was set as sticky, meaning that anything which tries to access it
will be reading wrong data here.
more useful information to provide is the last desk which the sticky
client was focused on, so update that upon focusing it

src/bin/e_client.c

@@ -3548,6 +3548,8 @@ e_client_focused_set(E_Client *ec)
 
    e_hints_active_window_set(ec->comp->man, ec);
    _e_client_event_simple(ec, E_EVENT_CLIENT_FOCUS_IN);
+   if (ec->sticky && ec->desk && (!ec->desk->visible))
+     e_client_desk_set(ec, e_desk_current_get(ec->zone));
 }
 
 E_API void