Resolve "VApps VHost can not be disabled"

Closes #4992

See merge request ispconfig/ispconfig3!1420

Resolve "SSL for nginx apps vhost"

Closes #6017 and #6007

See merge request ispconfig/ispconfig3!1422

Resolve "Trigger junk move by Subject line impacts forwarded emails"

Closes #6051

See merge request ispconfig/ispconfig3!1409

Add missing http2 directive to HTTPS proxy protocol config in nginx vhost conf

Closes #6047

See merge request ispconfig/ispconfig3!1406

Resolve "postfix: references non-existent sasl_passwd file"

Closes #6048

See merge request ispconfig/ispconfig3!1407

jailkit bugfixes

Closes #6041, #6036, #6040, and #6042

See merge request ispconfig/ispconfig3!1401

'Enable receiving' should check disablesmtp

Closes #6044

See merge request ispconfig/ispconfig3!1402

Resolve "Jailkit init template have syntax errors"

Closes #6039

See merge request ispconfig/ispconfig3!1400

Resolve "BREXIT - Update country list"

Closes #6046

See merge request ispconfig/ispconfig3!1404

Resolve "Syntax Error in OpenVZ module"

Closes #6045

See merge request ispconfig/ispconfig3!1403

Use standard_index.html as filename for the template index file (#5897)

Closes #5897

See merge request ispconfig/ispconfig3!1398

Resolve "Rspamd configured to learn bayes ham and spam by user"

Closes #6037

See merge request ispconfig/ispconfig3!1399

acme.sh and missing letsencrypt client fixes

Closes #6015

See merge request ispconfig/ispconfig3!1396

implement per-domain mail relaying

See merge request ispconfig/ispconfig3!1389

Merge branch '6031-rspamd-is-using-the-wrong-settings-for-add_header-rewrite_subject' into 'develop'

Resolve "rspamd is using the wrong settings for add_header / rewrite_subject"

Closes #6031

See merge request ispconfig/ispconfig3!1393