Stable 3.1



See merge request !484

add functions to 550-bind_dnssec.inc.php (see https://www.howtoforge.com/communi…

…ty/threads/dnssec-problem-expire-too-soon-ispconfig-3-1.74682/#post-351381)

See merge request !481

add functions to 550-bind_dnssec.inc.php (see https://www.howtoforge.com/community/threads/dnssec-problem-expire-too-soon-ispconfig-3-1.74682/#post-351381)

Fixed: #4307 The new LE ssl cert paths introduced in ISPConfig 3.1.1 where not set in the nginx_vhost.conf.master

fixed placeholders in system_config_misc



See merge request !478

Various 3.1 fixes



See merge request !477

- fixed some smaller things in plugins for apache and nginx

Corrected typo in french



See merge request !476