set_config function don't update is_dynamic row

in the set_config function, at the update query doesn't change is_dynamic row

In a MOD, at the install script (UMIL or not) when add a new variable to the phpbb_config table, the is_dynamic variable is not specified.

set_config($config_name, $config_value);

but in the MOD ACP module it is specified as true, but is not updated :

set_config($config_name, $config_value, true);

So it remain in the cache