Remove broken function from software_update plugin (#6103)

Closes #6103

See merge request ispconfig/ispconfig3!1443

Resolve "Dovecot not copied from conf-custom to dovecot/conf.d"

Closes #6096

See merge request ispconfig/ispconfig3!1441

Resolve "standard_index.html is not in DirectoryIndex list"

Closes #6099

See merge request ispconfig/ispconfig3!1442

Fix critical error with new custom Postfix config

See merge request ispconfig/ispconfig3!1440

Fix global enabling/disabling of relay host options

See merge request ispconfig/ispconfig3!1439

Resolve "Changing tag method in policy is not applied to spamfilter users"

Closes #5543

See merge request ispconfig/ispconfig3!1438

Resolve "Hide relay options per mail domain by default"

Closes #6088

See merge request ispconfig/ispconfig3!1431

Improve jk_init.ini

See merge request ispconfig/ispconfig3!1308

# Conflicts:
#   install/tpl/jk_init.ini.master

Resolve "Password lost emails not sent"

Closes #5865

See merge request ispconfig/ispconfig3!1434

Add --cert-name option to certbot calls to set primary domain instead of --expand

Closes #6061

See merge request ispconfig/ispconfig3!1418

Merge branch '6086-website-redirect-type-proxy-re-sets-to-no-redirect-when-switching-tabs' into 'develop'

Resolve "Website Redirect Type: proxy re-sets to No redirect when switching tabs"

Closes #6086

See merge request ispconfig/ispconfig3!1428

Fix query, dns_rr.name does not hold an fqdn

Closes #6083

See merge request ispconfig/ispconfig3!1424

Merge branch '6094-ignore-postfix_custom-and-dovecot_custom-config-files-in-conf-custom-check' into 'develop'

Resolve "Ignore postfix_custom and dovecot_custom config files in conf-custom check"

Closes #6094

See merge request ispconfig/ispconfig3!1436

Resolve "bind plugin should create slave subdirectory"

Closes #6070

See merge request ispconfig/ispconfig3!1435

Resolve "Update the contributing doc"

Closes #6049

See merge request ispconfig/ispconfig3!1408

Resolve "rspamd authenticated priority and misc"

Closes #6062 and #6053

See merge request ispconfig/ispconfig3!1411

Resolve "update.php removes _rspamd from redis group"

Closes #6089

See merge request ispconfig/ispconfig3!1427

Resolve "Add option to disable email welcome messages in server settings."

Closes #1804

See merge request ispconfig/ispconfig3!1429