Merge remote-tracking branch 'origin/develop' into 6113-undo-delete-mailbox

.gitignore

.gitlab-ci.yml

.gitlab/issue_templates/Bug.md

CONTRIBUTING.md

README.md

docs/autoinstall_samples/autoinstall.conf_sample.php

helper_scripts/cert_check.sh

install/dist/conf/centos52.conf.php

install/dist/conf/centos53.conf.php

install/dist/conf/centos70.conf.php

install/dist/conf/centos72.conf.php

install/dist/conf/centos80.conf.php

install/dist/conf/debian100.conf.php

install/dist/conf/debian110.conf.php

install/dist/conf/debian40.conf.php

install/dist/conf/debian60.conf.php

install/dist/conf/debian90.conf.php

install/dist/conf/debiantesting.conf.php

install/dist/conf/fedora32.conf.php

install/dist/conf/fedora33.conf.php