update to PHP 7.2 and remove mcrypt
update to PHP 7.2 and remove mcrypt

removed mcrypt because Rouncube uses openssl exclusively since version 1.2 and mcrypt was removed from PHP 7.2

kaiyou/freeposte.io,kaiyou/freeposte.io,kaiyou/freeposte.io,kaiyou/freeposte.io