Provide a default timeout of 5m to all ns_cache besed caches created via the acs-cache infrastructureBackground: in case, a db entry is to be cached, where the db querydoes not finish (e.g. runs into a deadlock), subsequent attempts forthe same value will be blocked as well by the mutex protecting theentry to be cached. Therefore, later requests to this entry might queueup in the server. By providing a timeout, this mutex will terminatelatest when the timeout is reached.The default value for the timeout is set to 5m. In case a certaincache might issue requests running longer than this, the cache hasto be configured with a larger timeout value.