Disabled sql-mode check in updater.

Fixed#5019 LE cert problem in mirror setups. This patch disables the creation of Let's encrypt SSL certs on mirrored slave servers.

remoting.inc.php

See merge request ispconfig/ispconfig3!777

Stable 3.1

See merge request ispconfig/ispconfig3!775

Added a third parameter to $app->log() function in server part to turn off logging to database and use this option in mysql lib to not log any server side SQL errors to the database.

Allow for serial to be increased when deleting any record in the zone

See merge request ispconfig/ispconfig3!773

- Fixed #5027 add support for PHP 7.1 and 7.2 on nginx servers in apps vhost.
- suppress some warnings in simplepie.inc.php

global option to enable pagespeed with nginx - allows to enable pagespeed even if no webserver-config is selected

add option to remote-api to increase the serial (Fixes #4930 #4806)

See merge request ispconfig/ispconfig3!772

Raised IDS block levels and set warn level to block level to avoid that the log gets filled with warnings.

Reseller is able to see a list of all clients and not just of his own clients in select field in the head of domain list when domain module is active.

add mail-relay and mail-transport to resync

See merge request ispconfig/ispconfig3!763