eldbus - fix warning for possibly undefined value being sent

this ensures the integer "id" is at least set before using it, though
reality is it will be set, it's better to have less warnings and there
isn't any other way to silence this warning other that setting it.

src/lib/elementary/elm_dbus_menu.c

@@ -695,6 +695,7 @@ _method_event_group(const Eldbus_Service_Interface *iface,
 
    while (eldbus_message_iter_get_and_next(array, 'r', &tuple))
      {
+        id = 0;
         if (_event_handle(dbus_menu, tuple, &id))
           return_error = EINA_FALSE;
         else