enforce unique mail_access source/type

interface/web/mail/lib/lang/pt_mail_blacklist.lng

interface/web/mail/lib/lang/pt_mail_whitelist.lng

interface/web/mail/lib/lang/ro_mail_blacklist.lng

interface/web/mail/lib/lang/ro_mail_whitelist.lng

interface/web/mail/lib/lang/ru_mail_blacklist.lng

interface/web/mail/lib/lang/ru_mail_whitelist.lng

interface/web/mail/lib/lang/se_mail_blacklist.lng

interface/web/mail/lib/lang/se_mail_whitelist.lng

interface/web/mail/lib/lang/sk_mail_blacklist.lng

interface/web/mail/lib/lang/sk_mail_whitelist.lng

interface/web/mail/lib/lang/tr_mail_blacklist.lng

interface/web/mail/lib/lang/tr_mail_whitelist.lng

interface/web/mail/mail_blacklist_edit.php

interface/web/mail/mail_whitelist_edit.php