Only last subscription request is synced

Currently emf_db_get_requests() makes an associative array out of the requests, using e-mail addresses as keys. When a user requested to subscribe for more than one list, only the request for the last list gets synced at next cron run, and so on. Multiple cron runs are needed to sync them all.
My suggestion to fix this is not to use the e-mail address as key for the associate array, unless a new parameter $lid is passed to emf_db_get_requests(), with which only the requests for a specific list are processed. Attaching a patch soon...