Merge branch 'develop' of https://git.ispconfig.org/ispconfig/ispconfig3 into...

install/dist/lib/centos_base.lib.php

install/dist/lib/fedora.lib.php

install/dist/lib/gentoo.lib.php

install/dist/lib/opensuse.lib.php

install/lib/installer_base.lib.php

install/sql/incremental/upd_dev_collection.sql

install/sql/ispconfig3.sql

install/tpl/master_cf_amavis.master

install/tpl/master_cf_amavis10025.master

install/tpl/master_cf_amavis10027.master

install/tpl/mysql-virtual_relaydomains.cf.master

install/tpl/server.ini.master

interface/lib/classes/remote.d/mail.inc.php

interface/lib/classes/validate_mail_relay_domain.inc.php

interface/lib/config.inc.php

interface/lib/lang/ar.lng

interface/lib/lang/bg.lng

interface/lib/lang/br.lng

interface/lib/lang/ca.lng

interface/lib/lang/cz.lng